Reinstalling the client should fix the issue. The installer modifies permissions of the Game folder to make it writable for everyone. It seems something restored these permissions, so the map downloader stopped working. Running the game as admin works too, but it's not a clean solution. Crysis contains serious security vulnerabilities, so its access to the system should be as restricted as possible. The built-in map downloader in Crysis Wars uses the "My Games" folder inside documents to store the maps. Maybe we should do the same? It's a bit messy, but no file permissions issues are there.