That was the full error description I got when I started SketchUp. But I just discovered that there was an update to SketchUp available, and after the update everything works fine (14.1.1282).
I did try to uninstall and re-install SU before, but apparently my installer was a not the latest version (14.0.4900).
Thank you for taking your time to read and reply to my post.
Ah, did you launch SketchUp by double-clicking a SKP file? We did have a bug in the first release of SU2014 where it caused some extensions to not load.