Thank you for your prompt reply.
I seem to be able to download youtube videos now. I tried a few downloads and it seems to be fine. The other thing I discovered which may help others that are still facing the problem is that instead of copying the link from the URL, use the "SHARE" button that appears below the name of the song and copy that link into your AIRY pop up and that worked for me. The only issue with that is that you have to download the song one by one.
My 2nd issue, is when I first installed AIRY, when I copied and pasted the link from the URL (not the SHARE), AIRY had a pop that would ask if I wanted to download the whole playlist or just that song. And when I chose playlist it would download the whole playlist. But then out of say 10 songs on the playlist, it would only download say 6 and the other 4 it would give me the error message I mentioned above.
But now it does not give me the pop that asks if I want to download the whole playlist - so I am forced to download each individual song using the "SHARE" option and copy and paste the link which is not convenient at all when you have like 200 songs on your playlist.
Please advise how I can set up AIRY that when I download, I want it to download the entire Youtube Playlist I created.