Here's an example of the issue: https://jsfiddle.net/x0rawz2o/
The video id in question is p3Geomh2EuY.
The video owner might have disabled playback from embed players but the iframe should be able to handle this issue and simply return an appropriate error code. In the end the player just breaks, become unresponsive and a cryptic unhandled error appears in the console: https://pastebin.com/LN8q6EY2
I tried forcing an update with cuePlaylist(), splitting the playlist with videoId and playlist options but in the end it's not the order in which the video id is added to the playlist but its very presence that causes a complete freeze. If this were a simple 404ed video I could just "ping" it with a fetch() to see if it's available and filter it accordingly but as I said this appears to be an unhandled error in the code of the script.