Whenever I relaunch Battle.Net I get the following error when trying to hit “PLAY” for Retail WoW.
The CAS system was unable to initialize. Tact instance creation failed. Error 16 container locked Tact: instance creation failed Error 16 Container locked.
This happens about 4-5 times after hitting “Play” and then finally it starts working. If I close Battle.net and reload it, that cycle starts over.
I am getting the same thing with Windows 11:
The CAS system was unable to initialize: Tact instance creation failed. Error
(1 6): container locked
Tact instance creation failed. Error (1 6): container locked
Sometimes I clear WoW cache and it works, other times no.
Cleared cache, windows restart didn’t work
Cleared WTF, windows restart didn’t work
Shutdown Windows, Started Windows, when I started WoW, it acted like I had never run TWW (showed video and such), but WoW started ok
I get CAS System Unable to Init whenever I have a download active in Retail and try to start Classic - or vice versa.
For me it appears to be a matter of Battle.net being unable to both download content for a game, and simultaneously start a different game.
HTH…