removing associations.

Arcee,
You can 'de-link' the users in the User Map area of JFBConnect. Simply check the row, and hit delete. Even if you re-associate a Facebook account to a different Joomla user, though, you shouldn't end up in a redirect loop like you're saying. I'm not sure what would cause that, but if you unlink accounts, and still run into issues, just let us know.

Thanks,
Alex

Administrators can definitely have Facebook connections. There's nothing in JFBConnect that prevents that, although we don't all anyone to login to the admin area using their Facebook account.

Can you try disabling any JFBCProfile plugins that you may have enabled? If you have some profile plugins enabled for extensions you don't have installed, that can cause 500 errors on your site. Beyond that, if you can recreate the problem easily, please set Error Reporting to "Maximum" and turn off GZip compression in the Joomla Global Configuration area. Then, when you login, instead of a generic message, you will hopefully get a specific PHP error that's preventing the page from loading. If so, let us know what that error is, and we can help figure out a solution.

Thanks,
Alex