Since Katalon 11.1.x, Windows.startApplication is broken

wistiti67 · April 8, 2026, 10:15am

Hello, since Katalon Studio 11.1.0 (and now, 11.1.1), I’m unable to start a Windows application.

When I start ‘Spy Windows Objects’ with paint.net for example (or any other executable), I get a popup with this message:

Unable to start application
Reason:
Cannot invoke “String.lenght()” because “spec is null”

Details:

java.util.concurrent.ExecutionException: java.net.MalformedURLException: Cannot invoke “String.length()” because “spec” is null
at com.kms.katalon.composer.components.impl.dialogs.ProgressMonitorDialogWithThread.runAndWait(ProgressMonitorDialogWithThread.java:49)
at com.kms.katalon.composer.windows.dialog.WindowsAppComposite$5.run(WindowsAppComposite.java:245)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:123)
Caused by: java.net.MalformedURLException: Cannot invoke “String.length()” because “spec” is null
at com.kms.katalon.composer.windows.spy.WindowsInspectorController.startApplication(WindowsInspectorController.java:176)
at com.kms.katalon.composer.windows.dialog.WindowsAppComposite$5$1.call(WindowsAppComposite.java:249)
at com.kms.katalon.composer.components.impl.dialogs.ProgressMonitorDialogWithThread.startThreadAndWait(ProgressMonitorDialogWithThread.java:36)
at com.kms.katalon.composer.components.impl.dialogs.ProgressMonitorDialogWithThread.runAndWait(ProgressMonitorDialogWithThread.java:48)
… 2 more
Caused by: java.lang.NullPointerException: Cannot invoke “String.length()” because “spec” is null
… 6 more

Same with the instuction Windows.startApplicationWithTitle() in script mode.

Everything worked fine with Katalon 11.0.1.

How can I rolling back to this version?

kazurayam · April 8, 2026, 10:55am

Please show your Groovy code around the line that caused

Caused by: java.lang.NullPointerException: Cannot invoke “String.length()” because “spec” is null

wistiti67 · April 8, 2026, 5:12pm

My full answer is in “waiting approval” since several hours.

For short, simply:

Windows.startApplicationWithTitle('C:\\Program Files\\``paint.net``\\paintdotnet.exe', 'Paint')

wistiti67 · April 8, 2026, 5:12pm

The above message was from a popup message, when lunching the app from the ‘Spy Windows Objects’ or ‘Record Windows Actions’ tools.

With a new test case with that code:

import static com.kms.katalon.core.checkpoint.CheckpointFactory.findCheckpoint
import static com.kms.katalon.core.testcase.TestCaseFactory.findTestCase
import static com.kms.katalon.core.testdata.TestDataFactory.findTestData
import static com.kms.katalon.core.testobject.ObjectRepository.findTestObject
import static om.kms.katalon.core.testobject.ObjectRepository.findWindowsObject
import com.kms.katalon.core.checkpoint.Checkpoint as Checkpoint
import com.kms.katalon.core.cucumber.keyword.CucumberBuiltinKeywords as CucumberKW
import com.kms.katalon.core.mobile.keyword.MobileBuiltInKeywords as Mobile
import com.kms.katalon.core.model.FailureHandling as FailureHandling
import com.kms.katalon.core.testcase.TestCase as TestCase
import com.kms.katalon.core.testdata.TestData as TestData
import com.kms.katalon.core.testng.keyword.TestNGBuiltinKeywords as TestNGKW
import com.kms.katalon.core.testobject.TestObject as TestObject
import com.kms.katalon.core.webservice.keyword.WSBuiltInKeywords as WS
import com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords as WebUI
import com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords as Windows
import internal.GlobalVariable as GlobalVariable
import org.openqa.selenium.Keys as Keys


Windows.startApplicationWithTitle('C:\\Program Files\\paint.net\\paintdotnet.exe', 'Paint')

I get (in the “Fail Reason” box):

java.lang.NullPointerException: Cannot invoke "String.length()" because "spec" is null

For trouble shooting, please visit: https://docs.katalon.com/katalon-studio/troubleshooting/troubleshoot-common-exceptions


Cannot invoke "String.length()" because "spec" is null (Root cause: java.net.MalformedURLException: Cannot invoke "String.length()" because "spec" is null
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)
	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)
	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)
	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)
	at Paint.run(Paint:20)
	at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)
	at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)
	at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:504)
	at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:495)
	at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:474)
	at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:466)
	at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:336)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)
	at TempTestCase1775650009471.run(TempTestCase1775650009471.groovy:30)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
Caused by: java.lang.NullPointerException: Cannot invoke "String.length()" because "spec" is null
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)
	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)
	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)
	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)
	at Script1775649326080.run(Script1775649326080.groovy:20)
	... 11 more
)
Test Cases/Paint FAILED.
Reason:
com.kms.katalon.core.exception.StepFailedException: Cannot invoke "String.length()" because "spec" is null (Root cause: java.net.MalformedURLException: Cannot invoke "String.length()" because "spec" is null
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)
	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)
	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)
	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)
	at Paint.run(Paint:20)
	at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)
	at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)
	at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:504)
	at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:495)
	at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:474)
	at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:466)
	at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:336)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)
	at TempTestCase1775650009471.run(TempTestCase1775650009471.groovy:30)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
Caused by: java.lang.NullPointerException: Cannot invoke "String.length()" because "spec" is null
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)
	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)
	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)
	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)
	at Script1775649326080.run(Script1775649326080.groovy:20)
	... 11 more
)
	at com.kms.katalon.core.keyword.internal.KeywordMain.stepFailed(KeywordMain.groovy:51)
	at com.kms.katalon.core.keyword.internal.KeywordMain.stepFailed(KeywordMain.groovy)
	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:92)
	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)
	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)
	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)
	at Paint.run(Paint:20)
	at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)
	at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)
	at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:504)
	at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:495)
	at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:474)
	at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:466)
	at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:336)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)
	at TempTestCase1775650009471.run(TempTestCase1775650009471.groovy:30)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
Caused by: java.net.MalformedURLException: Cannot invoke "String.length()" because "spec" is null
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)
	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)
	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)
	... 17 more
Caused by: java.lang.NullPointerException: Cannot invoke "String.length()" because "spec" is null
	... 23 more

The console view:

2026-04-08 14:06:53.085 INFO  c.k.k.c.l.logback.LogbackConfigurator    - Logback default configuration initialized from: C:\Users\xxx\.katalon\packages\KS-11.1.1\configuration\org.eclipse.osgi\150\0\.cp\resources\logback\logback-execution.xml

2026-04-08 14:06:53.089 INFO  c.k.k.c.l.logback.LogbackConfigurator    - Logback custom configuration initialized from: C:\DEVELOPPEMENT\KATALON\test3\test3\Include\config\log.properties

2026-04-08 14:06:54.112 INFO  c.k.katalon.core.main.TestCaseExecutor   - --------------------

2026-04-08 14:06:54.112 INFO  c.k.katalon.core.main.TestCaseExecutor   - START Test Cases/Paint

2026-04-08 14:06:54.621 DEBUG testcase.Paint                           - 1: startApplicationWithTitle("C:\Program Files\paint.net\paintdotnet.exe", "Paint")

2026-04-08 14:06:54.885 ERROR c.k.k.core.keyword.internal.KeywordMain  - ❌ Cannot invoke "String.length()" because "spec" is null (Root cause: java.net.MalformedURLException: Cannot invoke "String.length()" because "spec" is null

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)

	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)

	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)

	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)

	at Paint.run(Paint:20)

	at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)

	at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)

	at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:504)

	at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:495)

	at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:474)

	at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:466)

	at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:336)

	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)

	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)

	at TempTestCase1775650009471.run(TempTestCase1775650009471.groovy:30)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

Caused by: java.lang.NullPointerException: Cannot invoke "String.length()" because "spec" is null

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)

	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)

	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)

	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)

	at Script1775649326080.run(Script1775649326080.groovy:20)

	... 11 more

)

2026-04-08 14:06:54.894 ERROR c.k.katalon.core.main.TestCaseExecutor   - ❌ Test Cases/Paint FAILED.

Reason:

com.kms.katalon.core.exception.StepFailedException: Cannot invoke "String.length()" because "spec" is null (Root cause: java.net.MalformedURLException: Cannot invoke "String.length()" because "spec" is null

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)

	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)

	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)

	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)

	at Paint.run(Paint:20)

	at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)

	at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)

	at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:504)

	at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:495)

	at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:474)

	at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:466)

	at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:336)

	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)

	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)

	at TempTestCase1775650009471.run(TempTestCase1775650009471.groovy:30)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

Caused by: java.lang.NullPointerException: Cannot invoke "String.length()" because "spec" is null

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)

	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)

	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)

	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)

	at Script1775649326080.run(Script1775649326080.groovy:20)

	... 11 more

)

	at com.kms.katalon.core.keyword.internal.KeywordMain.stepFailed(KeywordMain.groovy:51)

	at com.kms.katalon.core.keyword.internal.KeywordMain.stepFailed(KeywordMain.groovy)

	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:92)

	at com.kms.katalon.core.keyword.internal.KeywordMain$runKeyword.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.startApplicationWithTitle(StartApplicationWithTitleKeyword.groovy:34)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword.execute(StartApplicationWithTitleKeyword.groovy:29)

	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:95)

	at com.kms.katalon.core.windows.keyword.WindowsBuiltinKeywords.startApplicationWithTitle(WindowsBuiltinKeywords.java:1371)

	at Paint.run(Paint:20)

	at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)

	at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)

	at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:504)

	at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:495)

	at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:474)

	at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:466)

	at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:336)

	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)

	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)

	at TempTestCase1775650009471.run(TempTestCase1775650009471.groovy:30)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

Caused by: java.net.MalformedURLException: Cannot invoke "String.length()" because "spec" is null

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory.startApplication(WindowsDriverFactory.java:83)

	at com.kms.katalon.core.windows.driver.WindowsDriverFactory$startApplication.call(Unknown Source)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy:35)

	at com.kms.katalon.core.windows.keyword.builtin.StartApplicationWithTitleKeyword$_startApplicationWithTitle_closure1.doCall(StartApplicationWithTitleKeyword.groovy)

	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

	at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:90)

	... 17 more

Caused by: java.lang.NullPointerException: Cannot invoke "String.length()" because "spec" is null

	... 23 more



2026-04-08 14:06:54.902 INFO  c.k.katalon.core.main.TestCaseExecutor   - END Test Cases/Paint

kazurayam · April 9, 2026, 12:08am

I am not able to suppor this.

I would pass this topic to Katalon.

→ @Elly_Tran

depapp · April 9, 2026, 2:40am

hi @wistiti67

this looks like a regression in 11.1.x where the internal path parsing fails
maybe you can try these workaround

1. How to Roll Back
You can download previous versions directly from the GitHub repository. No installer is needed; just extract and run the executable.

Download Link: Katalon Studio 11.0.1

2. Potential Workaround
If you need to stay on 11.1.x, try formatting the file path with forward slashes or the file:/// protocol. This often bypasses the URL parsing bug causing the spec is null error.

Standard: C:/Windows/System32/notepad.exe
Protocol: file:///C:/Windows/System32/notepad.exe

dineshh · April 9, 2026, 4:03am

Windows.startApplication/startApplicationWithTitle fails with "spec" is null due to broken path-to-URL parsing in FlaUI driver (line 83, WindowsDriverFactory).

Immediate Fixes

Windows.startApplicationWithTitle('file:///C:/Program Files/paint.net/paintdotnet.exe', 'Paint')

OR forward slashes:

Windows.startApplicationWithTitle('C:/Program Files/paint.net/paintdotnet.exe', 'Paint')

wistiti67 · April 10, 2026, 2:01am

No. I still have the same issue with

Windows.startApplicationWithTitle('C:/Program Files/Notepad++/notepad++.exe', 'notepad')

or

Windows.startApplicationWithTitle('file:///C:/Program Files/Notepad++/notepad++.exe', 'notepad')

Please note that the prefix ‘file:///’ fails with the version 11.0.1 either (response code 400)

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Immediate Fixes

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