I have two users who report that they are unable to launch their AutoCAD 2012, because no network license can be found. Those same users, and all my others, are able to get Revit licenses just fine. I looked at the NLM, did a status, and there are licenses available. I stopped and started the NLM, reread the license file, but to no avail. These users were able to get licenses earlier in the day. Nothing magical or strange happended in the intervening time.
The error they are getting is: autocad license error -15.570.0. These workstations can ping the server. I tried inputting the IP instead of the computer name. Nothing seems to work. I can't reboot that machine right now inthe middle of production, but that is my last resort.