Setup:
DomainA.DomainB.Local (2 Sites with a Single 2008R2 DC in each site)
TS1.DomainA.DomainB.Local (2008R2 main site)
TS2.DomainA.DomainB.Local (2008R2 main site)
This doesn't always happen but when it does it affects all domain users, occasionally when trying to RDP to TS1 all users get the error access denied with an ok button, if they click ok it just ends the session. This affects users in DomainA & DomainB (there are 4 users in DomainA that permanently use the TS to work and the majority of the time it is ok. when this happens even domain admins from either domain cant login (they all have access to the TS for RDP and can normally use it). If a domain admin logs in on the console that works and the Local administrator account can login locally or through RDP.
If i reboot the TS it will be fine and probably work for another week or two without any more issues, this is only affecting 1 TS and we have several in the Forrest (4 in this particular domain)