Finally upgraded my blog. Despite my presumption I did the upgrade with the automatic option of WordPress itself. And it failed miserably…..
I had no blog anymore and a 500 server error when I tried to access the admin pages. Uploaded some of the old files in an attempt to regain control. No progress..

Cleaned everything on the server and started all over with a manual install. Got it working this time.

Now updating all plugins and uploaded documents like pictures en pdf files….