We have integrated UFT Automation test cases from ALM to CloudBees Jenkins Enterprise using Add Ins: Micro Focus Application Automation Tools--> Execute HPE functional tests from HPE ALM.
When a particular test case ran for more than 2 hours there is disconnection between Jenkins and ALM and it gives Timeout error. The error message is

Unhandled Exception: System.NullReferenceException: Your Quality Center session has been disconnected. Contact your system administrator for more information
at Mercury.TD.Client.Ota.QC9.ITSTest.get_LastRun()
at HpToolsLauncher.AlmTestSetsRunner.GetTestRunId(ITSTest currentTest)
at HpToolsLauncher.AlmTestSetsRunner.WriteTestRunSummary(ITSTest prevTest)
at HpToolsLauncher.AlmTestSetsRunner.RunTestSet(String tsFolderName, String tsName, Double timeout, QcRunMode runMode, String runHost)
at HpToolsLauncher.AlmTestSetsRunner.Run()
at HpToolsLauncher.Launcher.RunTests(IAssetRunner runner, String resultsFile)
at HpToolsLauncher.Launcher.Run()
at HpToolsLauncher.Program.Main(String[] args)
An error occured while disposing runner: Your Quality Center session has been disconnected. Contact your system administrator for more information.