When I'm trying to add a new attribute set based on the default attribute set I get a complete blank page. When I reload this page I get an error message on the complete blank page: {"error":1,"message":"
This attribute set doesn't exist anymore<\/span><\/li><\/ul><\/li><\/ul>"}
Then returning to my overview page of my attribute sets, the new attribute set is there. But if I click on it, the whole set is empty without the inherited structure of the Default attribute set. Can someone help me, so I can set up a new attribute set based on the Default attribute set.