Active Directory – 2nd Domain Missing from Locations

Hello All,

We currently have two domains that have a trust relationship. Since a server reboot at the beginning of the week we still have the trust between two sites but when I try and assign a user to a new group only the domain I have connected to in AD is visible in the locations field.

Steps:
Select any user from the AD,
Select Member Of tab,
Select Add,
Select Locations

At this point the second domain should be visible. I have a feeling that this is related to the DNS but not sure where to look. I have only started back in IT support after a year stint as a developer so I am a bit rusty.

Many Thanks