Just upgraded my ZBT-1 to EmberZNet Zigbee 7.4.4.1, and I’m getting a few of these:
2025-04-14 11:25:48.016 ERROR (MainThread) [bellows.multicast] No more available slots MulticastId subscription
Everything seems to be working. Any idea what it means?
I’m afraid I can’t help you much, but I did spot this issue which might be related to whatever you’re seeing Upgrade to 2025.4.2 broke zigbee · Issue #142809 · home-assistant/core · GitHub
It means you are exceeding the controller’s capacity. Too many devices are trying to use multicast communication at once. If your devices seem to be working, then it’s a temporary error and should clear itself up. Try rebooting your controller and restarting Home Assistant.
How many Zigbee clients does your Zigbee network have and what controller are you using?
Twenty-seven routers and 36 end devices (how do you count client and server endpoints?). Home Assistant Connect ZBT-1.
I think you may be right that it’s a temporary problem. I got two or three short bursts of of errors after upgrading and rebooted several hours ago - nothing since.
Yes, I saw that, but it seemed to be related to an update of HA rather than firmware. I’ll keep an eye on it, though, thanks.
That doesn’t sound too large. Theoretically Zigbee can support a thousand total devices, but your coordinator and routers all have individual limits. Which are generally a corporate secret?
If Z2M or ZHA were affected in the core upgrade, that could generate a flood of multicast messages. But as you discovered, it will probably eventually settle down.
I am not an expert, and I am probably at least partly wrong. If anyone sees a problem with my analysis, I would appreciate being corrected.