Can't access Add Gallery / Images

Hey guys,

This gallery seems amazing! Unfortunately though I can’t use it.
The installation/activation went just great, but whenever I try to press on Add Gallery / Images, I get this.
It’s basicly a 404 page but it’s in dutch so let me translate:

Can’t retreive info

Reload – More
–

The error code is: ERR_EMPTY_RESPONSE

Managing the gallery works fine. Click

Please help me out 🙁 I don’t know how or why this happends.

Sincerely,

Arches

http://wordpress.org/plugins/nextgen-gallery/