Again, I've come across this annoying error (that gives you no clue to what's wrong). This time it occurs when I'm trying to access "Site Permissions" on a particular site in my site collection. Not all sites, just this one. I've searched all over for answers but have not found any solutions. I've also tried to access the role.aspx page directly and receive the same error. Oh, the error is "An unexpected error has occurred" if you did not see in the title. I did move this sub-site from one site to another (not site collection). All are under the same collection. I have moved many sites around as we have been restructuring our SharePoint site. May have issues with other sites but this is the one I've noticed and need to fix to adjust the permissions. A user needs access and I can't give it to them.
I appreciated all ideas and feedback.