DNN provider PowerDNN recently upgraded our DNN to 6.1.3. Now I can no longer manage my Users and Roles. For example when I click on add new user, I get:

critical error has occurred.Object reference not set to an instance of an object.

When I try to edit an existing user, same thing. I tried changing the skin for that page and still get the same error. My Admin\Events page shows General Exceptions and Page Load Exceptions. Get this when I pretty much try to do anything with the accounts. If I log in with my user account, I am able to change my own profile and password, thankfully.

Any help is greatly appreciated. I am totally new to this, be gentle :)

Mr E