500 Internal Server Error (although everything seems to work)

Yello,

although everything seems to work, i got too often this error ( on the website: http://kirkendick.startblog.eu/ ) :

“Found
The document has moved here.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.”

I updated my PHP, but that didn’t resolve the problem.

Wonder what’s wrong with it ?

Any help is appreciated.