Need your assistance. 

I am trying to enable External Authentication with Filemaker 14 Server. Application Server is member of Domain Controller  windows 2008. I have enabled "External Authentication" in the Database Server, Security. Database has external  server selected authenticated as, the group is added and the privilege is set to data entry.  Everything seems to be setup correctly and when trying to open external database it does not work. I have to enter the local file credentials to open database.  

One thing is that my group is not in the same location as the default windows Organizational Unit group,  this group is located in a different location within the Active Directory, do you think this might be the problem?  see AD groups below

 

the users are added to hese groups?  The OU location should not matter.

Can you log into the FMS OS with one of those user's AD accounts?

Update.  

When I open remote database that is on the Server via open remote. I get the window to enter credential.  I type my Active Directory account which is the same account I login with in my windows machine. my windows machine is member of the AD.  This is odd, that it does not do SSO but it does authenticate.  

Hi,  Yes the users are added to the group.  Yes I can login to the server with AD account.  

when opening remote database I still get the window to authenticate.  I have to enter the same account and password that I am login on workstation.

Have you tried doing a gpudate and relogging in from the clients?