"Battle.net is unable to identify your application version" in Wine (Linux)

Solution 1:

As mentioned above, the most common fix for this error is to right-click the exe and "Run as administrator".

But that doesn't fix it or if you're running wine, I was able to narrow the issue to the registry (wine regedit). Removing the two Diablo II folders (in HKEY_CURRENT_USER and HKEY_USERS) did not appear to work, so I blew both the "Software" folders (two levels up) and restored the Software folder from another wineprefix (instance of wine). Error's gone. It is likely that a fresh install would also work in this case--the main issue appeared to be a conflict between former Battle.net registry files and the patched exe.