We have upgraded our GW 8 System to GW2012 and one of the clients that have been upgraded is getting a D113 Domain not found error when she tries to send to a particular group in her Address book. If we try with the same group using a GW8 client then there is no problem with it.

If you ignore the error and say send anyway (after it asks if you want to go back and resolve the addresses that have been crossed out) then it all goes through.

Other address books seem fine, so it would point at that address book, but it works with GW 8 client.