Courses can not be backuped on my Moodle 3.7 anymore. It just shows that the process is pending:
Looking at my task log files, I see a problem with \core_course\task\course_delete_modules:
The log files says nothing unfortunately. Can I see in the database somewhere what's going wrong?
the first thing I'd try is to enable debugging in your site in order to get more details about which exact error you're getting there.
With that it may be possible to understand what's going. Still I'm not sure how both things (the failures in the adhoc task and the backups) can be related... but one thing at a time.
Hope debugging gives you some clue!
Execute adhoc task: core_course\task\course_delete_modules
... started 11:25:21. Current memory use 32.2MB.
(and here the Email just stops)
So I have no clue why this hangs... every minute.
and what happens if you execute the adhoc tasks from command line, with debugging enabled? Sort of:
php admin/tool/task/cli/adhoc_task.php --showsql --showdebugging --execute
Note that it's recommended to send all the output of that command to some file for later inspection (can be huge!)