https://bugs.winehq.org/show_bug.cgi?id=53697
--- Comment #42 from jhu543369@gmail.com --- (In reply to Stratos Panagiotidis from comment #40)
This fix worked for me, you have to run the old Agent which I did via duplicating my default Lutris config and pointing it to the old agent, running it then running the original bnet entry.
- Download that Agent.exe in another comment (edit: here
https://cdn.discordapp.com/attachments/538903130704838656/ 1020763521631404103/Agent_7984.zip)
- Rename/backup old Agent8009/Agent.exe and paste the new one there (ignore
the new Agent8012 and make sure you're not running the launcher)
In Lutris, right click your bnet entry and Duplicate it
Right-click on the duplicate entry, configure and point to the new
Agent8009/Agent.exe you downloaded.
Run the duplicate Bnet entry in Lutris to load the old Agent
Then run your original Bnet entry to load the launcher and it should now
update. Tested with WotLK Classic.
Have you tried simply removing the data/cache folder, copy the old agent.exe file into the Agent.8012 folder and then restart Battle.net?