Win32_TerminalServiceSetting Access Denied

Have you confirmed that this attribute is available to you when you customize a report in the Report Manager?  i.e. did it actually get added to the Reporter schema?

If yes, the issue could be on the computer side of things as WinRM (service that gives you access to the WMI data on the computer) is often disabled.   Are you currently successfully collecting any other WMI attributes?

You could test the latter access by making a simple Powershell script to test connecting to WMI on various computers using your Discovery credentials.

Re: extending the schema, I do see the class in the Extend Enterprise Reporter Attributes dialog. The class does not show up as an available field to add to a report.  I suspect this is because the field does not exist in the database because each attempt to read that class returns the "Error adding object to the database.  Access is denied.  (Exception from HRESULT 0x80070005 (E_ACCESSDENIED))" result.

Re: extending the schema, I do see the class in the Extend Enterprise Reporter Attributes dialog. The class does not show up as an available field to add to a report.  I suspect this is because the field does not exist in the database because each attempt to read that class returns the "Error adding object to the database.  Access is denied.  (Exception from HRESULT 0x80070005 (E_ACCESSDENIED))" result.

OK - when you are running the Configuration Manager, are you doing so as an account that is a member of the Reporter_Discovery_Admins or Reporter_Reporting_Admins AD groups?  These are the ones that should have the required permissions to modify the Reporter DB to add this new property.  If you have membership in one or both of these and you are receiving this error, then you need to go into SQL and check the permissions on the Reporter DB itself.

I misspoke above - it is the membership in the Reporter_Discovery_Admins that is the key one for adding the new property.