Drag'n Drop module errors.

I am getting these errors on the console:

TypeError: H5P.Transition is undefined
TypeError: H5P.DragNDrop is not a constructor

I already did the required PHP settings (memory and upload) and enabled the mandatory modules as you can see on my phpinfo page.
Still I can not get the Drag'n Drop module working fully. Is there a point to look further? I'd like to use H5P very much on my chess-learning site as it helps us with the production process quite much.
Thank you for any help or advice. best,

icc's picture

It looks like there might be some files missing. If you try opening up the network tab in your browser and reload the page, do you see any requests marked in red?