AddPackage Fails to return update was installed

Mar 3, 2015 at 11:17 AM
Hi
I'm using this API and it's great.
I am using it to update a windows embedded standard 7 machines.
I only have one small problem, one of the KBs (KB2937610) I'm updating returns a null references exception.
debugging the problem I found that this is an unhandled state in DismException.GetDismExceptionForHR because the HR returns 1 from NativeMethods.DismAddPackage
looking around this value is listed as Win32Error.ERROR_INVALID_FUNCTION.
checking the "add\remove programs->View Installed Updates" shows the update was installed.
also running the same code again shows this update to be installed.

here is the DismApi log for this update
Log.txt

Is Win32Error.ERROR_INVALID_FUNCTION the current value I should get?