Not able to run test case . browser terminated

Web Testing
1

Hello all,

I am getting below error despite of updating the browser and capabilities.

Warning: NLS unused message: QTEST in: com.kms.katalon.constants.globalMessages
Warning: NLS missing message: QTEST_NAME in: com.kms.katalon.constants.globalMessages
2025-09-28 09:44:44.426 INFO c.k.katalon.core.main.TestCaseExecutor - --------------------
2025-09-28 09:44:44.429 INFO c.k.katalon.core.main.TestCaseExecutor - START Test Cases/JS-SalesForceTC/SF
2025-09-28 09:44:44.655 INFO c.k.katalon.core.main.TestCaseExecutor - (Default) Username =
2025-09-28 09:44:44.656 INFO c.k.katalon.core.main.TestCaseExecutor - (Default) Password =
Test Cases/JS-SalesForceTC/SF
[Username:, Password:]
2025-09-28 09:44:46.910 DEBUG testcase.SF - 1: openBrowser(“”)
2025-09-28 09:44:47.102 INFO c.k.k.core.webui.driver.DriverFactory - Starting ‘Firefox’ driver
2025-09-28 09:44:47.200 INFO c.k.k.core.webui.driver.DriverFactory - Action delay is set to 0 milliseconds
2025-09-28 09:44:49.049 ERROR c.k.k.core.keyword.internal.KeywordMain - :cross_mark: Unable to open browser with url: ‘’ (Root cause: com.kms.katalon.core.exception.StepFailedException: Unable to open browser with url: ‘’
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.stepFailed(WebUIKeywordMain.groovy:175)
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:49)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.openBrowser(OpenBrowserKeyword.groovy:55)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.execute(OpenBrowserKeyword.groovy:37)
at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:79)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords.openBrowser(WebUiBuiltInKeywords.groovy:62)
at SF.run(SF:23)
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:486)
at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:477)
at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:456)
at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:448)
at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:322)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)
at TempTestCase1759067079928.run(TempTestCase1759067079928.groovy:25)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
Caused by: org.openqa.selenium.SessionNotCreatedException: Could not start a new session. Response code 500. Message: Expected [object String] “unhandledPromptBehavior” to be a string, got [object Object] {“alert”:“ignore”,“beforeUnload”:“ignore”,“confirm”:“ignore”,“default”:“ignore”,“prompt”:“ignore”}
Host info: host: ‘NYFC-REPORT-DEV’, ip: ‘10.0.0.4’
Build info: version: ‘4.28.1’, revision: ‘73f5ad48a2’
System info: os.name: ‘Windows Server 2012 R2’, os.arch: ‘amd64’, os.version: ‘6.3’, java.version: ‘17.0.14’
Driver info: com.kms.katalon.selenium.driver.CFirefoxDriver
Command: [null, newSession {capabilities=[Capabilities {acceptInsecureCerts: true, browserName: firefox, moz:debuggerAddress: true, moz:firefoxOptions: {binary: C:\Program Files (x86)\Mozi…, prefs: {remote.active-protocols: 3}, profile: UEsDBBQACAgIAJdNPFsAAAAAAAA…}, unhandledPromptBehavior: {alert: ignore, beforeUnload: ignore, confirm: ignore, default: ignore, prompt: ignore}, webSocketUrl: true}]}]
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:114)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:75)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:61)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:187)
at org.openqa.selenium.remote.service.DriverCommandExecutor.invokeExecute(DriverCommandExecutor.java:216)
at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:174)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:545)
at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:245)
at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:174)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:155)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:150)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:132)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:127)
at com.kms.katalon.selenium.driver.CFirefoxDriver.(CFirefoxDriver.java:22)
at com.kms.katalon.selenium.driver.CFirefoxDriver.(CFirefoxDriver.java:18)
at com.kms.katalon.core.webui.driver.firefox.FirefoxDriverBuilder.createDriver(FirefoxDriverBuilder.java:95)
at com.kms.katalon.core.webui.driver.AbstractDriverBuilder.build(AbstractDriverBuilder.java:53)
at com.kms.katalon.core.webui.driver.DriverFactory.startNewBrowser(DriverFactory.java:247)
at com.kms.katalon.core.webui.driver.DriverFactory.openWebDriver(DriverFactory.java:149)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.doCall(OpenBrowserKeyword.groovy:44)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.call(OpenBrowserKeyword.groovy)
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:41)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.openBrowser(OpenBrowserKeyword.groovy:55)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.execute(OpenBrowserKeyword.groovy:37)
at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:79)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords.openBrowser(WebUiBuiltInKeywords.groovy:62)
at Script1752600619796.run(Script1752600619796.groovy:23)
… 13 more
)
2025-09-28 09:44:49.058 ERROR c.k.katalon.core.main.TestCaseExecutor - :cross_mark: Test Cases/JS-SalesForceTC/SF FAILED.
Reason:
com.kms.katalon.core.exception.StepFailedException: Unable to open browser with url: ‘’
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.stepFailed(WebUIKeywordMain.groovy:175)
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:49)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.openBrowser(OpenBrowserKeyword.groovy:55)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.execute(OpenBrowserKeyword.groovy:37)
at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:79)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords.openBrowser(WebUiBuiltInKeywords.groovy:62)
at SF.run(SF:23)
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:486)
at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:477)
at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:456)
at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:448)
at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:322)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:151)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:139)
at TempTestCase1759067079928.run(TempTestCase1759067079928.groovy:25)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
Caused by: org.openqa.selenium.SessionNotCreatedException: Could not start a new session. Response code 500. Message: Expected [object String] “unhandledPromptBehavior” to be a string, got [object Object] {“alert”:“ignore”,“beforeUnload”:“ignore”,“confirm”:“ignore”,“default”:“ignore”,“prompt”:“ignore”}
Host info: host: ‘NYFC-REPORT-DEV’, ip: ‘10.0.0.4’
Build info: version: ‘4.28.1’, revision: ‘73f5ad48a2’
System info: os.name: ‘Windows Server 2012 R2’, os.arch: ‘amd64’, os.version: ‘6.3’, java.version: ‘17.0.14’
Driver info: com.kms.katalon.selenium.driver.CFirefoxDriver
Command: [null, newSession {capabilities=[Capabilities {acceptInsecureCerts: true, browserName: firefox, moz:debuggerAddress: true, moz:firefoxOptions: {binary: C:\Program Files (x86)\Mozi…, prefs: {remote.active-protocols: 3}, profile: UEsDBBQACAgIAJdNPFsAAAAAAAA…}, unhandledPromptBehavior: {alert: ignore, beforeUnload: ignore, confirm: ignore, default: ignore, prompt: ignore}, webSocketUrl: true}]}]
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:114)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:75)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:61)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:187)
at org.openqa.selenium.remote.service.DriverCommandExecutor.invokeExecute(DriverCommandExecutor.java:216)
at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:174)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:545)
at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:245)
at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:174)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:155)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:150)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:132)
at org.openqa.selenium.firefox.FirefoxDriver.(FirefoxDriver.java:127)
at com.kms.katalon.selenium.driver.CFirefoxDriver.(CFirefoxDriver.java:22)
at com.kms.katalon.selenium.driver.CFirefoxDriver.(CFirefoxDriver.java:18)
at com.kms.katalon.core.webui.driver.firefox.FirefoxDriverBuilder.createDriver(FirefoxDriverBuilder.java:95)
at com.kms.katalon.core.webui.driver.AbstractDriverBuilder.build(AbstractDriverBuilder.java:53)
at com.kms.katalon.core.webui.driver.DriverFactory.startNewBrowser(DriverFactory.java:247)
at com.kms.katalon.core.webui.driver.DriverFactory.openWebDriver(DriverFactory.java:149)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.doCall(OpenBrowserKeyword.groovy:44)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.call(OpenBrowserKeyword.groovy)
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:41)
… 18 more

2025-09-28 09:44:49.074 INFO c.k.katalon.core.main.TestCaseExecutor - END Test Cases/JS-SalesForceTC/SF

Please help to resolve this error.

Thanks

1 Like
2

kindly format your code block with three ` for better readability

aaaaaaaa bbbbbbbb
1 Like
3

Error “Unable to open browser with url: ‘’” and the Selenium SessionNotCreatedException indicates that the browser (Firefox) is failing to start a new session due to an incorrect WebDriver configuration—specifically, the unhandledPromptBehavior capability is set as an object, but Selenium expects a string value.

Solution Steps

1. Fix ‘unhandledPromptBehavior’ Capability

  • Go to your Desired Capabilities setup for Firefox in Katalon.
  • Change unhandledPromptBehavior from an object (like {alert: ignore, ...}) to a valid string (e.g., "ignore").
    • Correct:

json

{
  "unhandledPromptBehavior": "ignore"
}
  • Incorrect:

json

{
  "unhandledPromptBehavior": {
    "alert": "ignore",
    "beforeUnload": "ignore"
  }
}
1 Like
4

Hi @rjadhav,

Welcome to our community. Thank you for sharing your issue.

Can you share which Katalon version, WebDriver version you are using? Mostly this issue is caused by the wrong compatibility in WebDriver version. Please consider to upgrade your WebDriver and Katalon to the latest one. Thank you

5

Thank you . by adding this. Issue solved

1 Like
6

Yes i have updated the WebDriver and katalon . Issue solved by adding unhandledPromptBehavior as ignore.

Thanks

1 Like