Sleep transition timed out after 180 seconds while notifying clients about upcoming system capability changes.

I turned off "Enable Power Nap" and "Prevent computer from sleeping" in the Power Adapter settings and that worked for me. Not sure if it's one or the other or both, but that works for me for now.

Would be nice to not have such an issue on my brand new, very expensive computer though.

I had this issue on a brand new MBP 16inch, 2019. I tried reinstalling the OS but same issue. Once i upgraded to 10.15.5, i have not had any issues.

Same here. My brand new MacBook Pro 16" was running macOS Catalina 10.15.5 out of the box and it had the sleep issue from the moment I started using it before I had even installed any other software. I ultimately turned off PowerNap, as others suggested, and that did the trick. But this is clearly a widespread bug that Apple needs to address with the next release.

Just heard back from apple support, they said they're aware of the issue. They provided me some stopgap fixes to try:

• disable prevent computer from sleeping automatically when display is off
• disable power nap on battery and power
• unplug power cord before sleeping computer
• shut down computer before not using

I have tried the following, it's working fine so far for 2 days

• Disable power nap
• Unplug power Adapter if I'm not using the MBP
• Set the "Turn Display Off after" to 2 hrs with Power Adapter

Basically, not allowing it to turn on sleep mode with Power Adapter. May be good to take this approach before the bug fix is available.

I haven’t tried unplugging before sleep because that’s inconvenient for me, but disabling power nap has worked so far (2 days)

Same issue here, on a brand new MBP. Happens every day: I close the lid on the evening, and then open it in the morning and the computer reboots (saying a crash occurred). I'll try disabling Power Nap for now, while Apple doesn't come with a fix for the issue

What should I do? As I said before I had kernel panic panic(cpu 0 caller 0xffffff8011291b2c): Sleep transition timed out after 180 seconds while notifying clients about upcoming system capability changes.

Had because after disable power nap and prevent monitor.... everything works fine. One disadvantage is that after hibernation I can turn on Mac only with power button. Anyway that’s fine for me. I can work with these settings. Anyway I have still opportunity to send it back. Time till Friday. What would you do? Return or not?

Have tried the same thing and it works, however it's not practical for me when I need to charge overnight. Have found that plugging it in to charge does not affect system if I have fully shut down my MBP.

Was told to try:

Reset NVRAM or PRAM on your Mac 

How to reset the SMC of your Mac 

How to use safe mode on your Mac  

I even reinstalled the OS, but realised after a few days of monitoring that the error only occurred when I plugged it in and left in sleep mode.

I have the same problem, reboots everyday on my new MBP 16"

So, have you tried just unplug power cord before sleeping computer? Would it solve the problem ? Other mentioned options seem not practical.

I updated to MacOS Big Sur Beta it doesn't happen anymore..... :) ... even on 10.15 beta it didn't happen..... But on every single stable version update the crashes happen....:)

exact same new MBP 16" happened straight outta the box,

called Applecare, advised of the usual SMC reset, NVRAM reset if issue persisted to reinstall the Mac OS. All which I did and issue was still there. Not happy as its a brand new machine. Aftersales sent me a replacement, which I've set up last night. And the EXACT same issue. Not much point in sending this Mac again as it seems such a common thing. I'm as well to wait it out. I'm not setting up another machine from scratch. I didn't restore from the previous MBP set it up entirely as a new device.

panic(cpu 2 caller 0xffffff800d091b2c): Sleep transition timed out after 180 seconds while notifying clients about upcoming system capability changes. Suspected bundle: com.apple.iokit.IOGraphicsFamily. Thread 0x74.

same issue here, on a brand-new MBP 16".

I have the same issue, I've got all the crash logs here. I also had an issue where the Mac would not wake from sleep without using the power button. I managed to get around that by disabling the screensaver.

My Mac was a fresh install, nothing brought over from an old Mac.

The stop gap fixes suggested by Apple (i.e. shutting down every time) are not good enough for a £3k machine.