MySQL Database is crashing always at the same time

Behavior:
MySQL Database is crashing always at the same time

Solution:
The most likely cause of the crash is backup software. This also explains the constant time of the crash.
The MySQL directories (especially the data directory) may only be backed up if the database has been shut down before. A backup of this directory during operation always leads to a crash of the database. The .err file from the data directory of the database also provides information about the crash time.