I followed what this suggests (On your wiki) http://en.wiki.sureai.net/Enderal:LauncherDebugging and from there, it keeps telling me that enderal needs an update.
Do you have the newest Launcher? (1.1.2.9|A49)?
If the error still occurs upload your LauncherLog:
C:\program files(x86)\Steam\steamapps\common\Skyrim\EnderalLauncher\system\log\Launcher.log
If the error still occurs upload your LauncherLog:
C:\program files(x86)\Steam\steamapps\common\Skyrim\EnderalLauncher\system\log\Launcher.log


