Anyone interested in testing the party mode and scene support please join: https://github.com/openhab/openhab2-addons/issues/3393
CC: @teqnet, @AV_HomeAuto, @BigMountainSki
EDIT:
I ought to mention that after the upgrade you also need to adjust your thing settings because they are are now stored under a different name (see more info here). Because of that you need to set the IP/host address of your Yamaha on the Yamaha thing and assign the zone setting on each of the zone things.
If you configued via PaperUI go to > Configuration > Things > Yamaha Receiver > edit (pencil) > Address, and also Configuration > Things > Yamaha Main Zone > edit > Zone (set to ‘Main_Zone’). If you configured via the .thing file see the updated documentation here - note the host and zone are now all lower case.
In case you still have issues enable detailed logging and get back to me please.