Same problem here, still no luck. Was trying to update my current KSP 1.0.0 to 1.0.2 but launcher is stuck on Checking for Updates. The KSP-Steam installation was correctly auto-updated to 1.0.2 but I never touch that directory, I use it just to copy/paste on another location so I can manage various game versions. But I want to update my current modded game..... By the way the launcher is stuck as well on a non-modded KSP 1.0.0 game. The only thing I manage to do (but I fail as well) is delete Patcher.exe so the launcher is somewhat forced to re-download it. Then a UPDATE button appears. But clicking it runs the Patcher.exe that ask me user/pass of Squad Store... well, I dont have a Squad Store account as the game was bought with Steam, so I made an account. Well, stucked again. The Pather reports: "Unable to authenticate with the server: Received malformed data from the server: File not found." And this thing even i leave user/pass blank. So should be a game/serve bug..............