iMac crashes or restarts every night since upgraded to 11.7.4 two weeks (mid-Feb 2023) ago
iMac (Retina 5K, 27-inc, Late 2014) started crashing overnight after the update to 11.7.4. (also updated Safari to 16.3.1 at the same time). The iMac works great during the day. Seems it crashes if it has been left idle for a while and has gone to sleep. Weirdly, I'm no longer able to *manually* put the iMac in sleep mode: screen goes dark for 1-2 sec and then comes back on as if nothing had happened. In the morning, I either see the login screen (iMac auto-rebooted overnight), or the screen is dark and I've to hold the power button for 10 sec before the iMac reboots.
Typical error message:
panic(cpu 2 caller 0xffffff8011e5f82a): Wake transition timed out after 180 seconds while calling power state change callbacks. Suspected bundle: com.apple.iokit.IOGraphicsFamily. Thread 0x1124.
Failure code:: 0xe3696202 00000027
Called Apple Support and was told Apple no longer support that machine: it's considered a "zombie." Customer Service asked me to create a new user account, login a that user, and try to put the iMac to sleep. I did all that but still couldn't put the iMac to sleep. The Customer Service told me he couldn't help further. At my request, he emailed a link so I can install the original OS the iMac came with, and then try to update to the latest OS. (He reminded to backup all my files before then.)
This is a beautiful machine and I'd love to find a solution. I turned off the iMac one night and it turned on normally the next morning (short push on the power button). However, at some point during the morning it crashed and had to be rebooted. I can't recall if that happended when the iMac was in sleep mode.
Thank you!
iMac 27″, macOS 11.7
