Unable to open browser with url: ''

Hello guys. I am new to Katalon and I need your help. I am trying to do some simple web-tests. I do RECORD option and it works there.
However when I save RECORD and try to see LOG Viewer starting my case, it gives me error:
Elapsed time: 0,770s

Test Cases/case_1 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:64)
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:26)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.openBrowser(OpenBrowserKeyword.groovy:81)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.execute(OpenBrowserKeyword.groovy:67)
at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:56)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords.openBrowser(WebUiBuiltInKeywords.groovy:60)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords$openBrowser.call(Unknown Source)
at case_1.run(case_1:16)
at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)
at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)
at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:336)
at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:327)
at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:306)
at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:298)
at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:232)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:114)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:105)
at com.kms.katalon.core.main.TestCaseMain$runTestCase$0.call(Unknown Source)
at TempTestCase1556556211334.run(TempTestCase1556556211334.groovy:21)
Caused by: com.kms.katalon.core.exception.StepFailedException: No driver is set for execution.
at com.kms.katalon.core.webui.driver.DriverFactory.startNewBrowser(DriverFactory.java:213)
at com.kms.katalon.core.webui.driver.DriverFactory.openWebDriver(DriverFactory.java:188)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.doCall(OpenBrowserKeyword.groovy:74)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.call(OpenBrowserKeyword.groovy)
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:20)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.openBrowser(OpenBrowserKeyword.groovy:81)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword.execute(OpenBrowserKeyword.groovy:67)
at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:56)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords.openBrowser(WebUiBuiltInKeywords.groovy:60)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords$openBrowser.call(Unknown Source)
at Script1556554616011.run(Script1556554616011.groovy:16)
… 11 more

Someone can help me ? I tried different browsers, still the same error everywhere