I have built a custom block that loads a simple image, title and links to a file set. When clicking in the image a lightbox shows all the images in the file set.

It works great, although now all of a sudden, when editing the block and then trying to exit edit mode I get a note saying Access Denied??? I then need to log out and log back in.

My changes have been saved but the page is stilll in edit mode. If I exit edit mode from here without touching the block it all words fine? ANy ideas???