Register –> Page not found

Hello,

I hope someone can help.
My installed Plugins:

Advanced Custom Fields
bbPress
BuddyPress
Erident Custom Login and Dashboard
Jetpack by WordPress.com
Members
WP-Polls

When I installed the Members Plugin the option Options–>General–>Membership was false. Now I changed to true and if someone wants to register there turns the “Page not found”. I just asked Erident Custom Login and Dashboard. Look here: http://wordpress.org/support/topic/register-page-not-found?replies=2#post-5267386

I hope someone can help me with this problem.

https://wordpress.org/plugins/members/