When trying to launch the Diagnostic console using a specific account, the follow error is displayed. "Unknown error returned by SHGetFolderLocation". After clicking OK, the console opens and another error is displayed: "Access violation at address 0077D597 in module 'Spotlight.exe'. Read of address 00000000". The console is not usable and attempting to perform any action (ie, connect, click Help) results in the same error to be displayed.
Trying to run the Diagnostic Console with is successful and there are no issues.
This can be caused by a corrupt Windows Profile for the account that is attempting to run the Diagnostic Console.
Delete the Windows Profile of the account that is generating the errors, login to the Spotlight server again with that account and launch the Diagnostic Console.