Thread:Extension talk:MsUpload/MsUpload with MW V.1.20 shows "An internal error occurred"

Hi,

I installed MsUpload on my wiki. It's in use with the wikieditor. However when I try to upload a file (regardless if I use drag n' drop or not) it will show "An internal error occurred" when I try to upload it. Upload is allowed for all users, uploads are configured in php.ini, the file extensions are set and also java uploads are allowed. The image directory also got the correct permissions.

Any ideas? :)