Built Forest, however not able to add users from other domain in forest

When i try to give security permission to users from other domain on shared folder it given below error.

"The Active Directory Domain Controllers required to find the selected objects in the following domains are not available Ensure the active directory domain controllers are available and try to select the objects again"

Scenario, created 2 ways forest trust between forest on on-side and then used trust password and did same on other side.

I can see the users from other forest and its property but when trying to add the users getting above error.Any help appreciated.