The .Net Agent installer is not using information captured during installation to run the CA Introscope SPMonitor service and instead it always sets the LocalSystemAccount Logon context.
In Sharepoint FARM when installing SPMonitor through the .Net Agent installer, while registering the service, it should take the domain user, but it is taking the Local system credentials and thus is not able to get the farm details after starting the service.
Below are the error messages showing in the SPMonitor agent log:
[ERROR] [IntroscopeAgent.SPMonitorConstants] Exception while reading the farm version. Considering version 12 as default
[ERROR] [IntroscopeAgent.FarmDetails] Problem in getting farm details. Going to sleep for: 60000 ms.
System.NullReferenceException: Object reference not set to an instance of an object.
Before you run the .Net Agent installer, verify that the domain service account for running the Introscope SPMonitor Windows service has the following privilege in addition to the ones listed in the documentation:
"Log on as Service" privilege under the Local Security Settings.
This security setting determines which service accounts can register a process as a service.
To add security setting for the domain user account, run Local Group Policy Editor (gpedit.msc)
Security Settings-> Local Policies-> User Rights Assignment Log on as a service
This security setting allows a security principal to log on as a service.
Services can be configured to run under the Local System, Local Service, or Network Service accounts, which have a built-in right to log on as a service. Any service that runs under a separate user account must be assigned this right explicitly.
If you have already run the installer and the SPMonitor service is configured to run under the Local System account, you can change it to the domain service account for running the Introscope SPMonitor Windows service.