If your YouTube functionality is broken in Volumio this fix has worked for me, and others.
Enable SSH if you haven't already.
volumio.local/DEV/
or
IP-Adress/DEV/
-> SSH enable
It buggered me about in a couple of places.Start Putty
Login (default: volumio/volumio)
1: cd data/plugins/music_service/youtube
2: npm i fent/node-ytdl-core
3: nano package.json
4: change following line:
"ytdl-core": "github:fent/node-ytl-core"
to
"ytdl-core": "^0.29.2"
5: Ctrl+X -> Exit, Save
6: npm install
7: Reboot Volumio
Step 1 kept coming back as no such directory so I had to cd /data and then cd to the rest of the string one step at a time which fixed the problem.
P.S. If you need to ask how to do any of the above you probably shouldn't be diong it in the first place.