https://bugs.winehq.org/show_bug.cgi?id=47198
--- Comment #109 from harry harry+winehq@unheit.net ---
Keep in mind that, while i can start the client and play a game, I can not update the riot client: "Update failed: Failed getting path to current executable: File path could not be found in a mapped drive: ??\C:\Riot Games\Riot Client\RiotClientServices.exe"...
I did a fresh install without a problem. Since the client updates immediately after the install, and that worked, I assume that other updates should work, too. Didn't have another update since then, though.
I now got an update and I got the same error.
Workaround: instead of starting LeagueClient.exe, start the installer and hit "Repair". This will install the update and start the launcher.