Unable to connect error from katalon 7.2.1

Hi
i write a test case go to url and click some drodown elements.
i am using firefox browser.
when i run the test case the URL is not connected i have got an error called unable to connect Unable to connect

Firefox can’t establish a connection to the server

02-07-2020 12:01:46 PM Test Cases/FT_Components/Dropdown/Dropdown

Elapsed time: 30.846s

Test Cases/FT_Components/Dropdown/Dropdown FAILED.
Reason:
com.kms.katalon.core.exception.StepFailedException: Unable to open browser with url: ‘https://github.build.ge.com/pages/grid-foundation/gx-ui
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:72)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords.openBrowser(WebUiBuiltInKeywords.groovy:60)
at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords$openBrowser.call(Unknown Source)
at Dropdown.run(Dropdown:16)
at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)
at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)
at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:337)
at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:328)
at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:307)
at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:299)
at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:233)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:114)
at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:105)
at com.kms.katalon.core.main.TestCaseMain$runTestCase$0.call(Unknown Source)
at TempTestCase1581076903214.run(TempTestCase1581076903214.groovy:23)
Caused by: org.openqa.selenium.WebDriverException: Reached error page: about:neterror?e=connectionFailure&u=https%3A//github.build.ge.com/pages/grid-foundation/gx-ui&c=UTF-8&f=regular&d=Firefox%20can%E2%80%99t%20establish%20a%20connection%20to%20the%20server%20at%20github.build.ge.com.
Build info: version: ‘3.141.59’, revision: ‘e82be7d358’, time: ‘2018-11-14T08:25:53’
System info: host: ‘GCZC9088SZ7E’, ip: ‘172.17.53.113’, os.name: ‘Windows 10’, os.arch: ‘amd64’, os.version: ‘10.0’, java.version: ‘1.8.0_181’
Driver info: com.kms.katalon.core.webui.driver.firefox.CGeckoDriver
Capabilities {acceptInsecureCerts: true, browserName: firefox, browserVersion: 72.0.2, javascriptEnabled: true, moz:accessibilityChecks: false, moz:buildID: 20200117190643, moz:geckodriverVersion: 0.24.0, moz:headless: false, moz:processID: 2184, moz:profile: C:\Users\212765054\AppData…, moz:shutdownTimeout: 60000, moz:useNonSpecCompliantPointerOrigin: false, moz:webdriverClick: true, pageLoadStrategy: normal, platform: WINDOWS, platformName: WINDOWS, platformVersion: 10.0, proxy: Proxy(manual, ftp=pitc-zsca…, rotatable: false, setWindowRect: true, strictFileInteractability: false, timeouts: {implicit: 0, pageLoad: 300000, script: 30000}, unhandledPromptBehavior: dismiss and notify}
Session ID: eeea8b20-a02a-467a-8060-c169e3124b8b
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.createException(W3CHttpResponseCodec.java:187)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:122)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:49)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:158)
at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:83)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:552)
at com.kms.katalon.selenium.driver.CFirefoxDriver.execute(CFirefoxDriver.java:27)
at org.openqa.selenium.remote.RemoteWebDriver.get(RemoteWebDriver.java:277)
at org.openqa.selenium.support.events.EventFiringWebDriver.lambda$new$1(EventFiringWebDriver.java:105)
at com.sun.proxy.$Proxy8.get(Unknown Source)
at org.openqa.selenium.support.events.EventFiringWebDriver.get(EventFiringWebDriver.java:165)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.doCall(OpenBrowserKeyword.groovy:78)
at com.kms.katalon.core.webui.keyword.builtin.OpenBrowserKeyword$_openBrowser_closure1.call(OpenBrowserKeyword.groovy)
at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:20)
… 17 more