Problem solved.

The "postgres-9.6" service was down; don't confuse it with "postgres," which was up and misled me.
I must have made a mistake in my attempts to resolve this error (which is still present ).

Hello.
I'm having trouble with Waptserver installed on Debian 9.
It keeps crashing due to error 1/failure
(https://i.ibb.co/chdR292/fail.jpg

). Originally, the error was similar but with "Status=203/EXEC".
I managed to fix it by modifying the permissions on the server...