[TestComplete] Test runner exit code: -10 (Unable to create a user session).

My slave and Master Node is connected: but when I do build now: I get the following error. can anyone figure out why is this error?

Started by user unknown or anonymous
Running as SYSTEM
Building on master in workspace C:\Windows\system32\config\systemprofile\AppData\Local\Jenkins\.jenkins\workspace\tutorial

[TestComplete] The test execution started (LAC_Gilera/LAC_Gilera/JBL_LAC/Script|driver|runProjectAndGenerateReport).
[TestComplete] Found TestComplete/TestExecute installations:
	Type: TC, Version: 14.30.3743.7, Path: "C:\Program Files (x86)\SmartBear\TestComplete 14\x64\bin\TestComplete.exe"
	Type: TE, Version: 14.74.437.11, Path: "C:\Program Files (x86)\SmartBear\TestExecute 14\x64\bin\TestExecute.exe"
[TestComplete] Selected TestComplete/TestExecute installation:
	Type: TE, Version: 14.74.437.11, Path: "C:\Program Files (x86)\SmartBear\TestExecute 14\x64\bin\TestExecute.exe"
[TestComplete] Launching the test runner.
$ '"C:\Program Files (x86)\SmartBear\TestExecute 14\bin\TestCompleteService14.exe"' //LogonAndExecute //lDomain: "" //lName: "" //lPassword: ******** //lTimeout: "-1" //lUseActiveSession: "true" //lCommandLine: '""C:\Program Files (x86)\SmartBear\TestExecute 14\x64\bin\TestExecute.exe" C:\Workspace_t580\SDIG\SA_Test\AutoTests\LAC\LAC_Gilera\JBL_LAC\LAC_Gilera.pjs /run /SilentMode /ForceConversion /ns /exit /ExportLog:C:\Windows\system32\config\systemprofile\AppData\Local\Jenkins\.jenkins\workspace\tutorial\1622034637472.tclogx /ExportLog:C:\Windows\system32\config\systemprofile\AppData\Local\Jenkins\.jenkins\workspace\tutorial\1622034637472.htmlx /ErrorLog:C:\Windows\system32\config\systemprofile\AppData\Local\Jenkins\.jenkins\workspace\tutorial\1622034637472.txt /project:LAC_Gilera /unit:JBL_LAC /routine:Script|driver|runProjectAndGenerateReport /DoNotShowLog /JenkinsTCPluginVersion:2.6.2"'
[TestComplete] Test runner exit code: -10 (Unable to create a user session).
[TestComplete] [WARNING] Unable to find the log file "1622034637472.tclogx".
[TestComplete] [WARNING] Unable to find the log file "1622034637472.htmlx".
[TestComplete] [WARNING] Errors occurred during the test execution.
[TestComplete] Marking the build as UNSTABLE.
[TestComplete] [WARNING] Unable to publish test results (xml data is empty).
[TestComplete] The test execution finished (LAC_Gilera/LAC_Gilera/JBL_LAC/Script|driver|runProjectAndGenerateReport).
Build step 'TestComplete Test' changed build result to UNSTABLE
Finished: UNSTABLE