Will not shut down or upload LOTW

[K2GT]

Hello All,
I am having a shut down and LOTW issue. The program hangs up on shutdown and will not auto upload to LOTW. If I uncheck the auto upload button, it shuts down properly. I am using Log4OM2 v 2.20.0.0. The problem seems to have happened suddenly with no apparent reason. I shut down after operating a few days ago and everything was good. About 15 minutes later I went back on the air and the next time I shut down, the problem appeared. I checked the user guide and no configuration settings have changed, so I am at a loss. Any help would be appreciated.
Gus K2GT

[G4POP]

Does manual upload work from the QSL Manager?

[K2GT]

It does not. I receive the following error message:
INFO: ADIF File created successfully.
INFO: TQSL Version 2.5.9
No private TQSL Password set
Executing TQSL with upload
Messages from LOTW:
TQSL Version 2.5.9 [2.5.9]
Signing using Callsign K2GT, DXCC Entity HAWAII
There is no valid callsign certificate for K2GT available. This QSO cannot be signed on line 9

On the other hand, it uploads properly if I use TQSL. Thanks Terry.

[G4POP]

You either need to update the TQSL config or there is something not set correctly in the Log4OM configuration/external services/LOTW menu