I have something really strange going on.
Of course it may be my own fault, but I can't figure out what I did wrong.
I made a new template and applied it to a new site.
When I am in de backend and click on Editing > Properties I don't get the usual lightbox, but a plain text form. Like the css is missing.
What can I have done wrong here?
When I apply one of the standard themes it works fine again.
What did I do wrong here?