no longer can't add new users

Hi!
A few weeks ago I added a new user to my multisite. With the User Role Editor Plugin I created a type of user with some access characetristics. I added this user to the sites I wanted it to admin. Everything was working fine. This week dunno what happened this user no longer couldn’t manage his sites. I’ve already uninstalled the plugin, upgraded the network, etc etc etc. I tried again to add a new user using only WP features but when I try to add the user as admin on the specific sites this role doesn’t appear on the list (in fact any roles appears!). In the users tab it says it has two users but the new user does not appear on the list. I received the email saying a new user was created but when we try to login it says user doesn’t have permition to access… It’s weird because it worked fine once, no changes were made and now nothings works! What can I do??