The issue was that if you logged in after mid-october, although the files were changed on the server, the file cache list didn’t update when the client connected (it was saved in the profile and it got looked up instead of the fresh data), so it always believed to be downloading an earlier patch file, and the downloaded file never matched the one which the server was telling it should be. I figured one of the files were not updated by the script I was running so a forced update make everything to be in sync again.