Uploading videos issue Plus listing field empty

Tried on a few occasions to upload a small mp4 video, without success. I receive on each occasion the following error:

Error: SyntaxError: Unexpected token < in JSON at position 0

Also, on the Listing Page (https://cklwebhosting.com.au/video/add-listing/) there is no option to do anything under Listing Details. A small field opens, but you cannot enter any information into it.

I would appreciate any comments/feedback/miracle cures. 🙂

Site: https://cklwebhosting.com.au/video

Cheers
Mike