by Marius S.
UPDATE: Tryed to make cli autobackup with Skipped hidden courses and skipped courses which didn't change during 365 days. So course ID=49 was skipped, but on course ID=249 we got same error and autobackups stopped.
Again from server older backups was not deleted, they just haven't been display in Restore course page.
Apache has rights to delete files, moodledata and coursebackups directories has chmod 777. Backup files in coursebackups directory are with chmod 666, so it shouldn't be permissions issue.
Thanks,
M.