Hi. I'm nearing the end on my sanity on this and would really like some feedback.
I recently got a 2018 15 MBP, the machine had Big Sur on it and was working perfectly. I installed High Sierra as I need to run some old software. Seemed to go fine ( although a curious extra partition appeared after the install called 'Update' which seems to contain NVRAM and firmware related files - can find virtually no info on this online)
But anyway the big problem is the machine crashes on shutdown or restart ~75% of the time. It just hangs with the spinning wheel. Have to press and hold the power/touch ID to shutdown. Doesn't matter if it's shutdown via the Apple Menu or Terminal: sudo shutdown -h now.
Tried NVRAM reset, SMC reset, uninstalling non-Apple extensions, safe boot to clear cache, creating and booting into new user accounts, booting into recovery and repairing the disk and containers from there (it said all ok apart from crypto val warnings on Macintosh HD). Have booted into verbose mode to try to get a more thorough picture from logs but as I'm writing I haven't triggered the crash on shutdown yet while in verbose mode. Also tried a bunch of suggestions people have written over time for this sort of thing, deleting login.plist and so on.
Regular logs don't show anything too different to me although I can post a relevant chunk.
Some people who have had similar problems claim to have fixed this one way or another, but nothing has worked so far. Considering reinstalling High Sierra. But I have seen some people say a reinstall didn't fix it!
Wonder if FileVault is the problem here which I turned on probably on the 2nd or 3rd reboot after installing HS. Or if installing HS over Big Sur has created some kind of mess. Wonder if there could be a firmware mismatch where T2/BridgeOS had been updated with later firmware that isn't 100% compatible with HS? Also this machine did get a complete refit by Apple before I got it, I think the touch bar was part of that refit.
Machine works flawlessly until it's asked to shutdown or restart.
Any advice appreciated. Many thanks.
I recently got a 2018 15 MBP, the machine had Big Sur on it and was working perfectly. I installed High Sierra as I need to run some old software. Seemed to go fine ( although a curious extra partition appeared after the install called 'Update' which seems to contain NVRAM and firmware related files - can find virtually no info on this online)
But anyway the big problem is the machine crashes on shutdown or restart ~75% of the time. It just hangs with the spinning wheel. Have to press and hold the power/touch ID to shutdown. Doesn't matter if it's shutdown via the Apple Menu or Terminal: sudo shutdown -h now.
Tried NVRAM reset, SMC reset, uninstalling non-Apple extensions, safe boot to clear cache, creating and booting into new user accounts, booting into recovery and repairing the disk and containers from there (it said all ok apart from crypto val warnings on Macintosh HD). Have booted into verbose mode to try to get a more thorough picture from logs but as I'm writing I haven't triggered the crash on shutdown yet while in verbose mode. Also tried a bunch of suggestions people have written over time for this sort of thing, deleting login.plist and so on.
Regular logs don't show anything too different to me although I can post a relevant chunk.
Some people who have had similar problems claim to have fixed this one way or another, but nothing has worked so far. Considering reinstalling High Sierra. But I have seen some people say a reinstall didn't fix it!
Wonder if FileVault is the problem here which I turned on probably on the 2nd or 3rd reboot after installing HS. Or if installing HS over Big Sur has created some kind of mess. Wonder if there could be a firmware mismatch where T2/BridgeOS had been updated with later firmware that isn't 100% compatible with HS? Also this machine did get a complete refit by Apple before I got it, I think the touch bar was part of that refit.
Machine works flawlessly until it's asked to shutdown or restart.
Any advice appreciated. Many thanks.