I have the Zip folder but can’t watch the video

If you downloaded the files delivered in a ZIP folder, once the download is finished, double-click to extract the files to a folder before trying to open them. You won’t be able to read or watch a zipped file without extracting from the ZIP folder.

If you’ve downloaded into Dropbox before installing a ZIP file app first, you may have to delete it from Dropbox and reload it before the ZIP app will be able to access it.