Highly annoying issue, and almost impossible to track down. The error message is useless, might as well say "ERROR: Something is wrong. "
Iāve been a little out of touch with the HA community but when I was getting similar errors, it was related to running on the Piā¦ it just couldnāt handle everything that I was doing within my HA. That was a Pi 3B, prior to the 3B+ coming out so not sure about that. My solve was to switch to a more powerful pc (than the Pi)ā¦ My HA has been running flawlessly on a i3 in a docker instance for almost a year alongside other processes. I suspect you could get away with an odroid or similar slightly stronger setup than PI depending on your exact configuration.
The Pi seems strong enough, but sureā¦it could be a possibility. I would have migrated to a x86 platform, but my stuff is mostly z-wave, and Iām using the razberry board, and I really do not want to replace the controller, and have to redo the entire zwave setup (painful). The errors do not seem to cause any problems that I can tell, but something is obviously struggelig.
It would be nice of homeassistant could have slave instances/agents, offloading a lot of work to other servers (this was available at one time, i rememberā¦,.early versions).
Update:
Just an FYI. I was noticing āunder voltageā errors when switching to the B+, so I just replaced the power adapter i had with the āofficial PIā PSU, and the regular out of sync errors, seems to have stopped (I did get one on startup and one trying to check logbookā¦which tends to fail). But it seems better.