500 unexpected error : Editing Resource mailbox Issue

Not able to edit resource mailbox in 2013. Issue is not for all resource mailbox only for few resource mailbox's it gives me error 500 unexpected error . Request could not be completed. any idea we are migrating from ex2007 to 2013 When we create new resource mailbox in Ex2013 there is no issue

Version of Exchange 2007 sp3 roll12, Ex2013with rollup 4 . All resource mailboxes are on Ex2013