I have trouble updating to 2.4.15, i had 2.3.4 updated to 2.3.5 finally to 2.4.15.
Now it's not possible to edit posts, backup does not work.

I have tried to do a new installation of 2.4.15, I get the same error...

I have the prefix mlf05_ in the db

Was a reply to this posting in the 2.4-release-thread.