Windows 2012 R2 Domain controller, dcdiag error, dsbindwithspnex() failed with error 1727

Hi,

I have 3 sites linked over a VPN tunnel.  In one of the remote site DC, I am getting the error "dsbindwithspnex() failed with error 1727" when I run DCDIAG.  Basically the remote site DC with the error cannot connect to the FSMO owner in the primary site.  The primary site tunnel device is Cyberoam and remote site tunnel device is TMG 2010 (Enforce strict RPC compliance is unchecked on TMG rule & System policy rule).  I only have this one DC in the remote site.  A quick search results in solutions such as system restore

Any ideas about how to fix the issue.

Regards

Mathew