Dokuwiki cannot add new users when subscription rule contains group @user (default for new users)

[badookey]

Hi.

I am using Dokuwiki 2018-04-22b "Greebo". When I create an automatic subscription rule for namespace ':' (all), for group '@user' (default), I cannot create new users, the page goes blank until i retract the request. I can browse other dokuwiki pages fine in other tabs. When I manually remove the rule or this plugin the issue doesn't occur. This happens when adding a user via the 'register' button AND via the 'add user' fields under user management.

I believe the plugin may be trying to update the subscription rules while dokuwiki is creating the account creating a deadlock that means the user is never created in the first place.