I'm use system cron. Run every 5 min with command
Have problem with every extension which use cron and write admin log.
For example, this string:
and cron locks.
My post on forum: https://www.phpbb.com/community/viewtopic.php?p=14302461#p14302461
I tested this with another two extensions and had the same errors.
and the first: https://github.com/ForumHulp/emailonbirthday