WPDM Dropbox Explorer not saving files

Hi,

I’m having an issue with Dropbox Explorer addon. I’m able to attach a file through ‘select from dropbox’ within the file post type as usual. however I just spotted today that when I update the file post, the attached file doesn’t save and I’m presented with “No file uploaded yet!”.

This is consistent on two of my websites. Both were working over a week ago. Any ideas what may have introduced this issue?

Thanks in advance.
A