Delete SkyrimEditor.ini and SkyrimEditorPrefs.ini from your Skyrim folder.
This caused the Creation kit to throw an error about version control.
"Version control is enabled. A network location must be selected to proceed.
Select OK to locate a ConstructionSetNetwork.ini file and continue."
Pressing OK > can't find the file specified anywhere in the Skyrim folder.
Pressing cancel > "Version control can be disabled by setting bUseVersionControl to 0 in the ConstructionSet.ini file." - and the program doesn't start.
Help? Thanks!
EDIT: And now the whole program keeps crashing on me when I try to load my companion mod. Getting some errors about armor with the name "", so I guess I fuxed up somewhere before.
The creation kit seems to really dislike me, I haven't been able to create almost anything because of all the hassle with errors and problems...