Region Timeline in GridView - Adding a video does not work

When I click on video, nothing happens. Also concerns other like image, audio, etc.

That seems to be correct, it applies to all media based modules - although ‘Library’ should work so it would seem that in the grid view you can’t open the upload form - https://github.com/xibosignage/xibo/issues/1162

Thank you for bringing this to our attention.