Latest Update Breaks Site

Hello, we updated module to 7.x-3.0-rc6 and it broke our web site, specifically it throws out 500 server error code. Weird thing is, when site is in maintenance mode if you are not logged in you see maintenance page, but if you are logged in all you see is blank page. To make it even more weird half of the admin area is visible, content, structure, appearance, etc... but config area is not visible unless module is disabled. When enabled config area is blank.

Tried deleting it, reverting, rolling back database, installing different versions, nothing helps

We are using drupal 7.65

We don't see any specific errors about this issue in our log