1. Download this file and save it to somewhere you won't forget: http://users.on.net/~link22/Diablo/agent.db
2. Copy and paste this into a windows explorer address bar C:\ProgramData\Battle.net\Agent\
3. Copy the file you downloaded from step 1 into that folder, You will be prompted asking if you want to replace the file, click yes replace.
4. Run your client and the patch will go through.