P: Slow UI when using Mac and Custom Display Profile

Yes, the bug doesn't affect all Mac's; zero issues on my 2019 MacBook Pro 15". 

After experiencing extremely slow performance with LR10.1, perpetual spinning beach balls and occasional crashes using my 2018 iMAC (Mojave 14.6) I switched to my MacBookAir (mid-2013, also Mojave 14.6) and performance is back to normal. ???????

Thanks for your good wishes - I do hope they will be heard... 

It certainly does look like a complex issue, but at least at my end, it's readily reproducible - which means to me that Adobe by now must have a test system that falls in the same category. Now they just have to figure out how to fix it - hopefully before the developers and Q/A-folks disappear into their well-earned Christmas holidays. Keeping my fingers crossed...

*Ron_Pfister Thank for posting this. So now I really have no ideal why LR10.1 is now fast in Library on my old 5.1 box. New 7.1 also is working fine. Hope it stays that way. Just hope Adobe gets this figured out for all you that suffer through this.

Here a quick update from my end: I've recently performed a clean install of Mojave 10.14.6 on my MacPro5,1 (upgraded to 2x 3.46GHz, 64GB, RX580 8GB, NVMe SSD) without using migration tools of any sort. I only migrated my LR settings, not the prefs. I also re-calibrated my displays, resulting in new ICC-Profiles. When using the new profiles or the default ones provided via DDC by the displays, there is absolutely no change in LRc 10.1 compared to the old install: library functionality is painfully slow. So I'm back to using the sRGB profile on my secondary display. Just in case this this is of relevance to anyone from Adobe who might be reading this: on my previous boot partition, I had CS6 installed, now I don't. So that doesn't seem to be a factor.

Adobe, pretty please get this sorted ASAP - it's a proper nuisance!

On closer examination of more detailed images, you definitely lose fine detail in low-resolution mode (not surprisingly).  So, I guess you have to pick your poison until we have a fix - lose color accuracy by assigning sRGB as the display profile, or lose fine detail by opening in low-resolution mode...

Based on earlier suggestions I tried checking the "Open in low resolution" option in the Finder "Get info" panel for the Adobe Lightroom Classic application.  When I re-started Lightroom, the performance was greatly improved.  At least for me, this is a much better workaround than assigning an sRGB display profile (in fact, I haven't been able to see much of a difference between running in "low resolution" and "high resolution" mode for my work yet).  This is on a 2020 27" iMac running on Catalina with only the native display.

Yesterday I went back and tested LR10.1 on the old 5.1 box with the AOC monitor. No slow down it was fast. Since the old NEC PA127W could no longer hit 5000K or get above 80cd/m it was replaced on the main new 7.1 box. So I connected the old NEC PA127W to the 5.1 box using the same custom profile as before and tested it with LR10.1. I found it to be fast with no slowdowns as before with AOC connected. I decided to sleep on my finding and analyze this for awhile.

My thoughts now are that there is some possible caching corruption going on. Possible even font display that is triggered by LR10.1 that isn't by LR9.4. On the 5.1 box the OS is exactly the same as before when LR10.1 was extremely slow. Only thing I did was have another monitor on it for a while. I am thinking that possibly seeing that new monitor changed the caches or ini files that the driver/OS uses for display settings. This would could explain the randomness of this slowdown and why some see changes when going to sRGB or the Low Res setting and why it makes no improvement for others. 

Since now I no longer have this problem I can not test this, but for those of you that can here is what I would do. 

If you have another monitor hook it up. If LR10.1 is now fast go back to your regular monitor.

If you don't have the ability to hook up another monitor, flush all your caches to see if that will make any difference. 

@ Rikk 

Hello Rikk,

I have changed the monitor setting to both sRGB and AdobeRGB. Both did not bring success. If I move the slider of e.g. Dynamic several times from right to left it suddenly hangs. It takes more seconds until the program reacts again. From this point on, lightroom reacts only very slowly. Also, the preview is no longer displayed correctly. In my last attempt, the edited image was displayed with a green bar that took up about a quarter of the image. I can also send you the lightroom system information text file.

I was so excited when I saw there was an update to lightroom from v 10 to 10.1. I thought, I hoped, its the fix we have all here been waiting for... sadly no. If anything I feel it is even slower, no improvement at all. 

When will this be fixed??? So frustrating. And now on top of that I have gotten an email that my subscription price is changing from January. Its going up!! Why do I (and others) have to pay more for less? 

This is a huge bug surely we can expect a fix soon?

Since Christmas is fast approaching perhaps it is Father Christmas I should be asking and not adobe so "Dear Santa I wish for Christmas a lightroom version 10.xx that works..." 

😉