desktop with Apple hardware
Friday, September 25, 2020 at 1:55pm

Operation: Reload the Computer

By Niki

This weekend, I’ll be taking on the monumental task, of reloading my Mac. I do not look forward to this task. It is not what I would consider fun. I do not do such things for giggles.

But why torture myself like this?

Why? Because I've been dealing with a... quirk, ever since I upgraded from Mac OS High Sierra, to Catalina. Which (looks at a calendar), has been since around Christmas. When I got my new iMac - which incidentally did not have Catalina on it, so I had to upgrade.

This quirk? Well really I would consider it a bug. One that is apparently unacknowledged by Apple. One that seems to plague even their own displays (according to posts out on the internet)!

What is it already?

The flashing display upon wake.

To be clear, I'm not speaking of just the built-in display on the iMac, although it is an unfortunate party to this problem. It's an external monitor that I have hooked up to my iMac to extend my desktop. It's a 27" monitor from Acer. Not very expensive, not 4k or 5k or anything like that, but it does its job.

With my previous iMac, it worked a charm - wakey-wakey from sleep, iMac! Sign in, a brief blip while the iMac registers & recognizes the monitor, and away I go. Golden.

With Catalina? Wake the iMac. AAaaand before I can even sign in, the flashing begins. The Mac tries really hard to identify the monitor. We watched a temporary *.icc file named "Nameless-Display-" followed by a bunch of alphanumeric characters, be created & destroyed in the Displays directory while the Mac tries to figure out what it is supposed to do with my monitor. Meanwhile, both the external monitor and the iMac screen take turns toggling on & off. If I have windows that were active on my external monitor before my iMac went to sleep, those will 'jump' over to my main iMac screen when it can't detect what the external monitor is. Then they will disappear again when it thinks it has it... only to flicker off again and reappear on my iMac once more. Back and forth, back and forth.

The folder where that file appears/disappears:

The only solid way I've found to fix this? Turn my monitor off, before waking the iMac. Sign in, then power on the monitor.

What solutions did we try?

Before deciding to resort to a reload, I tried several different "tricks" that users on various forums suggested to other users who were reporting the same or similar issues. To be clear, there are a couple different 'flashing display' issues out there. One is supposedly tied to Firefox. Another, the monitor just flickers like there is a power or cable issue. Another where it appears the video card is glitchy. Then there's the one I am having.

The various recommended solutions varied from... "Try a different HDMI cable" (check). "Try a different HDMI > Thunderbolt adapter" (mine is brand new). "Try a safe mode boot" (check). And the most recent that my husband found, "Try deleting these specific files in these two different locations" (we can only delete the ones under the user Library, not the System>Library! Those are super uber protected, you can't even delete those from the command line).


From what my husband was finding out on the 'net, apparently the issue stems from those *.icc files existing pre-Catalina, and NOT being overwritten in an upgrade because they already exist (and probably also due to the file protections, I'm guessing).

We determined there was probably some solid truth behind that, after we hooked up my external monitor to two different Macbooks - one that used the same HDMI > Thunderbolt adapter that I use with the iMac, and the other the old HDMI > Display port adapter that my old iMac used. On both Macbooks, neither had been hooked up to an external monitor before, and they both had Catalina installed. Both worked perfectly with the external monitor, most critically in the "wake from sleep" state.

How annoying!

Yes, yes it is.

There's an additional issue this problem may be causing, and it's with my mechanical keyboard (Corsair K95 Platinum). Once in a while, if I forget to toggle my monitor off before waking up my iMac (like hitting a key by accident while I'm working on the dayJob laptop), the screen flipping will cause my keyboard's special color actions to just stop working. The color will freeze, and any effects (like the ripple on keystroke) don't work anymore. I can't even toggle between color profiles. The fix? Unplug the keyboard, plug it back in.

Now, this could be coincidence and only slightly related to the external monitor problem, but the only way to find out, and to fix the external monitor issue, is to reload.

So. If you'll excuse me, I need to start going through my files and making backups of the stuff I need to keep. Make notes of the programs I need to reinstall, particularly for the web development side of things. And try to make sure I don't forget anything important.