Thanks for your reaction! The problem is I don’t use them. My package / page description only contains ‘test’. This problem only comes when I create a new template.
Thanks, this fixed my problem! However I still have another problem. When I create a new page template, all my page templates are buggy due to a PHP error. (http://c.codeconverters.nl/image/352b3q1x0d3S)
It shows the newest page template (which I just made) on top and it shows the configured page template at the bottom.