Add Listing no longer working in 8.9.4

Hi all,

After having upgraded to 8.9.4. and wordpress 4.6 last weekend, I’ve noticed that the “add listing” page is no longer working. The page does not show the listing packages anymore. It only has an empty frame as you can see the following page (or see attached screenshot): https://www.onewebdirectory.com/add-listing

Same goes when I want to edit an existing listing. It just shows the empty frame. I’ve rolled back to last weeks version and there it’s all working fine.

I’m using Directory Press and the Caesar child theme. Can anyone please help me with this? Currently no one can add listings to my page!

Thank you!

Kind regards,
Philipp