Cron url doesn't allow underscore _ in domain name
If you create a site tralal_po.domain.ltd, and then try to add a cron that calls a script like: http://tralal_po.domain.ltd/cronscript.php, you will get an error.
If you create a site tralal_po.domain.ltd, and then try to add a cron that calls a script like: http://tralal_po.domain.ltd/cronscript.php, you will get an error.