Catalina beta 5 causing late 2015 iMac to freeze when left unattended

Since this only happens when I return to my comptuer, I assume there is some kind of bug with power-saving features? In any even my screen will be frozen, keyboard and mouse unreponsive, and the magic trackpad isn't even doing its fake click anymore. Reading the console messages is, as usual, unhelpful.

Post not yet marked as solved Up vote post of bergmayer Down vote post of bergmayer


I'm having this exact issue with my MacBook Pro Early 2015 in Catalina beta 5. I haven't been able to figure out what exactly causes it, but after a few minutes of not interacting with the computer, the trackpad can no longer be clicked, keyboard doesn't appear to work, and the display freezes. The only option is to hold the power button to restart.

Each of the 3 times this has happened I've been running Safari, the latest Xcode beta (5) + simulator, Music, Terminal, Sketch, and Visual Studio Code. On AC power, with iPhone connected via USB. I haven't been able to duplicate the freezing in Safe Mode.

I set the computer to stay awake and it keeps happening, so it must not be a power saving thing.

Same problem, Early-2015 MacBook. Hasn't happened with an iMac Pro.

I strongly suspect Xcode 11 beta 5 is the culprit but there seem to have been general performance regressions in Catalina beta 5. Simulator in Xcode beta 5 when using SwiftUI preview either brings performance to a crawl here or it causes a kernel panic

Here's an update based on my testing:

I disabled my screensaver to see if it had any effect, and it still froze exactly 6 minutes and 8 seconds after I left it alone.

Let it sit once again after a restart. Again: 6 minutes, 17 seconds.

Third: Unplugged power. 18+ minutes of no activity, no freeze. It's now been on for over 3 hours now and still no freeze.

It appears that if the device is plugged into power, it freezes after a few minutes if left unattended.

Post not yet marked as solved Up vote reply of sjk Down vote reply of sjk

Same here with a MacBook.

+1 with MacBook 2015 freezing

Same herewith my Macbook

Same here with my 2015 Macbook Pro..


thanks for the hint with the power issue.

Since I had to keep power connected while file vault is encrypting a large external drive (it pauses encrypting without power connected) I thought I could eventually keep my MacbookPro (early 2015) from any sleep phases by running "Amphetamine". Activated an indefinite session and went shopping.

Now, 75 minutes later, I came back - and all was still running.

Maybe it helps as a workaround.

Same here with my MacBook Air.

But this bug keeps appearing since beta 4.

Anyway I also made some kind of experiment. I launched a Mac, opened a system activity app and CleanMyMac widget to have the info about CPU usage and its temperature, and processes which it takes up.

I left my Mac alone, then CPU suddenly started to have usage about 85-100% and it started to raise its temperature. It had 45°C on start. Fans weren’t working.

Some minutes later Mac stopped working, the screen froze over and now the fans started to run. CPU’s temperature was 68°C. And the first process in system activity, sorted by the most CPU usage was “photolibraryd”, so I think there’s something wrong inside photos app.

I’m using iCloud Photos, the option “optimize disk space” on this Mac is on, and the library itself is big (about 63K photos), and it takes about 200GB on iCloud. Photos app was saying that it is sorting my photos, maybe that’s what it makes my Mac hot-froze over?

Moreover, after reset I launched the system activity app and I was constantly killing the photolibraryd process, but it kept "healing" and turning back to the procesess list. So I was killing it as this process wasn't appearing on the list. And now everything is normal.

I encourage you to do the same experiment on your Macs.

Sorry for my mistakes in English if they appearaed. Polish guy here.

Two Macbook Pros Early 2015 with latest Catalina Beta 5 and almost identical software installations. One freezes, the other one works fine.

Unplugging the power cord stopped the freezing for me as well. I am using a 2015 MBP as well and just started seeing this behavior in beta 5.

Running the Aphetamine app on the one of two Macbook Pro which freezesseems to make the trick; so it is a Power Management issue.


same here with a MacBook Pro (Retina, 13-inch, Early 2015)