Is your game updated to the latest patch? If not, please do that:
http://social.bioware.com/page/da-patches
You should also try to start the game as administrator.
Last but not least you can try an official suggestion from this thread (I know that the thread is about DA2, but it is still worth a try):
EV#52973 – Some are getting a AWC.dll error
- Early reports suggested that this was due to an outdated version of the Windows .NET Framework, but we no longer believe that to be the case. Instead, we now believe it to be related to Admin accounts. Some users are reporting that the issue is resolved by creating a new user with Admin rights in the Users control panel, then logging under that account to install and validate the game. After having done that, they were able to log back into their regular account to play the game.
