Hello,
We are currently migrating from Exchange 2010 to Exchange 2013. So far, not many problems, except this one.
For OWA and ActiveSync coexistence, some Exchange 2010 users cannot log on to Exchange 2013 OWA. Exchange 2013 should serve as a proxy to Exchange 2010, it works for new users, but not for old users with many groups.
After checking the logs, I identified the source of the problem:
https://support.microsoft.com/en-us/kb/2988444
So on all my Exchange 2010 CAS, I changed the values of MaxFieldLength and MaxRequestBytes to the one defined by Microsoft:
MaxFieldLength: from 65534 to 65536
MaxRequestBytes: from 16777216 to 65536
After a reboot, problem is still the same. After checking, it seems from the start I had the highest value for both properties from the start...
What can I do to make it work for all users ? Do I need to touch to Kerberos TokenSize attribute ?
The easiest solution would be to delete groups, I know, but this is something I can't do.
Thank you
Franck