If you have installed bbpress or other plugins and then get the error "You do not have sufficient permissions to access this page" where you are not able to successfully login to /wp-admin on your site, you may try the following to regain access to your site.
The bbpress plugin has a known issue where the user permissions get changed and when you try to login it gives the "You do not have sufficient permissions to access this page" error message instead of loading the dashboard.
***** Please be sure to backup your database before resetting user roles *****
In the case of bbpress it is only the dashboard that is locked out. Once you try to login and have got the above error message, try adding this to the end of your domain name while the error still shows:
/wp-admin/plugins.php (ie... yoursite.com/wp-admin/plugins.php)
As long as you entered the correct user/pass then you should see the plugins page after entering that url.
If you have OptimizeMember installed and activated, you will need to reset the user roles. To do this, please go here: "OptimizeMember > General Options > Define Membership Levels & Packages" and then scroll down near the bottom of that section till you see a grey button titled "Reset Roles/Capabilities" - Once you click that, then it should restore user roles to the WordPress default and you should be able to regain access to the main Dashboard page.
If you do not have OptimizeMember installed or resetting roles in OptimizeMember doesn't fix the issue, you can try one of the following plugins to help with this also (highly recommend "User Role Editor" plugin below):
Please note that OptimziePress bears no responsibility for what these plugins may do to your database so we always suggest taking a backup anytime your site files or database may be effected - in case you need to restore those if something doesn't go quite right.
Also, please review this discussion on bbpress forums for more information about how users have been able to deal with this issue with bbpress.
If you have any questions about this please feel free to submit a support ticket and we'll be glad to help answer those for you.