ProjectWise API aapi_Login returns ERROR# -1608455648 (Worked about 2 months ago in the same versions of code and PWiseExplorer)

Login via Projectwise via aaApi_Login was able to connect with a logical account while running in a Windows Service 2 months ago. This stopped working since.  The error returned from the login api ls:

Error -1608455648 : Cannot login to the datasource.

 

Knowns:

Worked 2 months ago  

SAME version of ProjectWise Explorer for all tests: 10.0.3.167  (unsure about Connection Client differences)

SAME Login works in standalone executable, but not when launched as a windows service.

Questions: 

- What is the cause of the seemingly spontaneous new failure of login?

- What type of error is -1608455648 and what does it mean?

- If no answer is readily available, is there any additional debugging information that could be gathered (beside connection client version) or tests that should be run to figure out this issue?