Ok I am running out of ideas on this one got a user that is having issues using a custom mmc. I compared the user group membership with a user that works ok.
My problem user is a member of 129 groups and my other user member of 75 groups. By a lot of digging about and testing I find if I remove any 3 groups from one particular OU it works , this OU has 66 groups in it . If I take user out of any other Groups not in this OU it does not work. I found this after a google afternoon

Well, there is a known issue where if a user is a member of too many groups they can overflow the security token, but that's usually after someone is a member of 120 groups or more


anyone got any suggestions where to go next in fixing this issue