Mopidy disconnects when playing in Iris web frontend

When I have just installed the Iris http frontend. But when I push the play button on any track, mopidy crashes.
sudo systemctl restart mopidy
restarts without issue

Raspbery PI 4.19.75-v7l+ #1270 SMP

Mopidy v2.3.0 (2019-10-02)

Iris version: 3.41.2

Any ideas why this might be happening?

You don’t say if anything was running before trying Iris so I’m not sure if this is relevant, but it might be worth checking * failed to open vchiq instance

Hello Steve
thank you for replying. I added mopidy to the groups and it seems to have solved the issue. Many Thanks for your help