dzigakaiser's profile

96 Messages


1.8K Points

Fri, May 1, 2020 7:16 PM

Lightroom Classic/ Win 10: Group into stack on large amounts of photos - very slow and unreliable

Hey there,

I recently noticed that my LR Classic locks up for quite a while when grouping larger amounts of photos at once (500-4000 photos) and I was wondering if this can somehow be optimized.

With up to around 1000 photos, LR does work after a long waiting time of around 5-10 minutes.
When going higher in image numbers, it seems rather unreliable.

As an example, I just grouped 3800 images and this locked up LR for about 10-15 minutes, then it shows the images as a stack and you would think you can continue working but when you try to go to a different folder it is stuck on "Loading..." in the library view and the "Metadata" section has the small turning loading circle.

When I check the resource monitor on Windows 10 I see a background process called "lrperformance.db-wal' which is writing to disk at pretty consistent 8000-9000 B/sec and a possibly related process called "ActivitiesCache.db-wal", also with very low read and write access.

The CPU load is 1% and overall disk usage on all disks is below 1MB/s. 

At this point I have no clue what LR is doing and why it is not loading anything.
After another 15 minutes of nothing happening in LR I close it. It closes without any warning of still doing something in the background.

I think "Oh, okay. Maybe it got confused and I actually just have to relaunch it", so I try to launch LR Classic again but nothing happens and I don't see any LR process running. I wait a small moment and try to launch it another time.

This time it tries to start but warns me that the catalog is still open in another application and I shall close the other application first. I guess, something is still accessing the database in the background, just that I don't know what it is doing and how long this is going to take or if it actually crashed along the way and now is not letting go of the database.

The only options I have now is to wait indefinitely to see if at one point I can open the catalog or to restart my workstation and then start LR again.

I am curious as to what operation is actually happening under the hood when photos are stacked? I would think it is a rather fast procedure and does not require too much database adjustment but somehow this does not seem to be the case.

My setup:
Win 10 Pro
Threadripper 3960x
Catalog on a NVME SSD

Update: I restarted the workstation as the warning of the catalog being open in another application was the only thing I've gotten for the past 20 minutes and now LR Classic launched and the photos are stacked as expected. The only unexpected outcome is that LR did not remember where I left off and showed the same start folder as the previous time I launched it. So, i guess something did get stuck and kept the catalog database open even after I closed LR Classic. This happens quite frequently when I try grouping many files.

Anyone with similar experiences or tips? I appreciate any info, ideas and help!

Take care,


Accepted Solution

96 Messages


1.8K Points

7 m ago

Issue still persists.

Just came back from a trip with a few timelapse photo series' and 360x180 panoramas.

What happens:

1. Selecting 800 photos of a timelapse.

2. Group into stack. Takes a small amount of time to show the group stack.

3. LR does not show any sign of doing anything but the only thing I can do is browse the same library folder I was in. Nothing is loaded from disk (clicking a photo won't show its metadata, you cannot enter develop mode). 

4. I wait 30 minutes and then quit LR. It shows the popup that it hasn't finished writing metadata but that it will continue next time I launch LR. Here lies the next problem.

5. LR UI closes but the process continues running for another 5-10 minutes or sometimes as long as the user does not manually end it in task manager. As long as the process is running a new instance of LR cannot be launched. When it is ended, LR will complain that the catalog is in use and cannot be opened. The only way to get back, as described before, is to restart the workstation and do the whole circus over again.

Mind you that stacking 300 photos is a matter of seconds, so 800 should not take 100x/1000x as much time. Everything points to it getting caught up in some background process. This has to be a fixable bug...

Can someone please take a look at this?



Adobe Administrator


10.2K Messages


137.2K Points

Please install Lightroom Classic 10.0 which was released earlier today. Does it affect your issue?

Adobe Photography Products

Quality Engineering - Customer Advocacy

96 Messages


1.8K Points

Hey Rikk,

thanks for your reply.

Admittedly, I was very hesitant to try the new big update and planned to wait a week or two to see how the other users react. But since the issue makes working a real pain, I just gave it a shot and to my surprise it actually seems to work flawlessly.

Just grouped 5800 photos, it froze for just 15 seconds and then I was able to continue using LR normally.

Thanks for the update suggestion. I more and more stopped risking updates throughout the past year, mainly because of PS and not LR, though.

I am very happy to see improvements in some areas.

Kind regards,


953 Messages


14.4K Points

1 y ago

Do not you have think that stacking up is not envisaged to pile all pictures of a file, but normally only existent pictures of the single original????
To regroup the photographs which go together, there are collections....



1K Messages


15.8K Points

1 y ago

I just stacked 250 photos and it took about 5 seconds.  I don't really care to try more as I can't imagine why there is a need to stack this many photos.  

96 Messages


1.8K Points

1 y ago

Thanks for your input.

Well, at first glance it seemed to be a convenient way to quickly group separate 360x180 panoramas in the library view after a day of shooting. That is around 250 images average and for this it worked well. 

Adding timelapse shoots to the mix you are easily talking 1500 images that are visible when browsing the folder and I prefer to stack them so I can browse the day without having to scroll through each image of the timelapse :)

I use collections as well but it simply is adding a lot of overview to be able to group and collapse those groups when going through the folders.

Since it is clearly possible to stack also thousands of images and the issue just lies in something bugging out after the operation is done, I wouldn't go so far in assuming that there is no use case to it or that it wasn't meant to be used this way.

I am not quite sure what you mean by "to pile all pictures of a file, but normaly only existend pictures of the single original", Yves. I am talking about the grouping functionality. And I am relatively certain that this is perfectly capable of being used to regroup images in the folder view in addition to creating collections.


1 Message


60 Points

I am also having issues with stacking becoming slow to the point I have force quit and restart. Sets of 3 images in a 150 image folder. Has been going on for a couple of weeks and most recently with the new update.

One suggestion for your timelapse is to give the first image of a sequence a color label. Then view in grid view with a filter. Since you are selecting all images to stack you might as well create a new folder for each sequence since this is needed for a timelapse workflow anyways.