Have configured multiple Automation Point servers using Windows Security for remote Viewer to allow users from a single domain to have access and have used the same steps on all servers.
However, user login is only successful for some of the servers.
For a problem server, the output file apDiag.zip ("C:\ProgramData\CA\CA Automation Point\Logs") from running Diagnostic Report contained event log file application.evt which showed error:
Logon failure (1385) domain_name\user_name
Per Microsoft Windows System Error Codes (1300-1699), error code 1385 indicates a logon rights problem:
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ERROR_LOGON_TYPE_NOT_GRANTED
1385 (0x569)
Logon failure: the user has not been granted the requested logon type at this computer.
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Resolved problem by using Windows Local Security Policy > Local Policies > User Rights Assignment and enabled "Allow log on locally" for the domain users.