From the VideoPlayer help (click the ? at the appinventor), it says:
"You can also set the media source to a URL that points to a streaming video, but the URL must point to the video file itself, not to a program that plays the video.
At the “blocks” I set “VideoPlayer1.Source” to http://XX.com/tube/city.mp4 (i cover my source with XX)
At the “design” set Source = None
When testing it said “undefined” when I click Button3.
If I upload the city.mp4 from appinventor
At the “blocks” set VideoPlayer1.Source to city.mp4 (no URL, just filename)
At the “design” set Source = None (yes None)
It plays the video when i click Button3.
So VideoPlayer CAN’T work with URL as it says in the help (the ? mark). Is there something you are going to fix? Thanks for a great product.