https://sureai.net/forum/viewtopic.php?t=10187
[...] or the launcher displays that everthing is installed but you can't start the game, go to this directory: C:\program files(x86)\Steam\Steamapps\common\Skyrim\EnderalLauncher\system\config.sur. Edit the file (it's a textfile) with e.g. Notepad++ in this way: replace the "sCurrentVersion" with an older version (safest: "1.1.0.0").
Reizeii wrote:Try to click on Settings in the launcher and Save setting. It worked for me, its weird.