I've googled this for a few hours now and I haven't been able to solve this problem.
Domains are ole.local and ept.local. Two way domain trust. Trust type = Forest, Transitive = Yes.
Both domains have stubs in DNS to resolve to each other. I can ping the root domain ole.local from ept,local and it resolves with one of ole.local's DNS servers and visa versa. I can add a user or group (from ept.local) to the ACL of an ole.local shared folder on any of the three Windows 2008R2 or 2012 servers at OLE.
I can add a user or group (from ole.local) to the ACL of a ept.local shared folder to all (server 2008 and 2012) but one server 2008R2 machine. When I try this on any of the folders on this machine I get the error "The Active Directory Domain Controllers required to find the selected objects in the following domains are not available: ole.local"... I have confirmed that I can ping from this server the root of the ole.local domain. Again I can add an ole.local user on the other servers at ept with no issue.
Can anyone shed some light on this situation?