There is nothing about it on mediawiki.org ''Policy restriction in effect. The fifth parameter is disabled on this system''! My provider ''one.com'' does not support the fifth parameter. Since I upgraded from 1.15 to 1.24.1 I am not able to register any new members on my wiki. (php 5.6)
One.Com is not supporting the 5th parameter as it is vonurable to spam (their words - not mine)
//► User:RoanKattouw Gave me advise on this:
UserMailer.php does in fact attempt to work around this But it only knows to do that when safe_mode is enabled. So maybe your system has safe_mode off while still having the restriction
In includes/mail/UserMailer.php on line 321 you should see $safeMode = wfIniGetBool( 'safe_mode' );
Try changing that to $safeMode = true;//
This was all I needed. And I got it working again. As One.Com is one of the largest hostingproviders I believe that many more will have this problem.
I hope this will be verified by you.
Kind regards,
Robert de Jong