I can't figure this out, uploading an image when i am editing or adding a page doesn't work correctly. During upload i get a http error. Debugging shows async-upload.php gives a 500. The funny thing is the image is uploaded. When i refresh the page and hit "add media" i can see the image in the library, but without the important "meta" data as ATTACHMENT DISPLAY SETTINGS >> size. And i notice size should be defined for the gallery to work properly.
How can i fix this?