I have atttempted to upload one of my scores to YouTube, both times the playback has been severly mangled.
When I upload a specific score from Musescore to YouTube, the thumbnail of the usual staffs full of music is replaced by staffs with no music and cut off a little after; the audio is delayed and never finishes; the video is replaced by the image described above after the title screen and before the Musescore logo at the end; and lastly, the playback scroller at the bottom of every YouTube video basically goes the lenth of 3 minutes and 18 seconds in 14 seconds and abruptly stops and buffers about half-a-second before the end. Because of this last problem, the audio never gets a chance to finish. I made the score by first altering a Musescore 2 score in Musescore 3. After that, I decided to open up a new score in Musescore 3 and copy from the original thinking that maybe Musescore had trouble putting old software into a usable YouTube video. The issue is still looming and I do not have the ability to test this out more than once every 24 hours since I am not a premium member. I have not tried uploading another score as my time restraints still apply. A picture of both the botched thumbnail and playback scroller, my original Musescore 2 score, and my new Musescore 3 score will be attatched. Here is the link to the YouTube video: https://www.youtube.com/watch?v=qVCY3TiFV7A