Updated to LR Classic v15.0 and program is now extremely slow.

[Rlrood]

After installing LR Classic the app is now so slow that it is unusable. Windows 11, strong PC.

[Rafael Aviles]

Thank you, John. I know how to get to the Library folder, but the file is not there. Here is a screen shot of what is there.

[johnrellis]

@Rafael Aviles,

LR Classic (and nearly every app that uses the Apple app frameworks) always creates a persistent .plist file.  It's present on your system, but your Finder isn't displaying it. 

Your screenshot indicates that Finder isn't showing you all the contents of the /Users/<user>/Library/Preferences folder.  It's not displaying any .plist files, just .plist.lockfiles, which haven't been used in many years.  Unfortunately, the screenshot omits much useful information, so I'm not sure what's causing your Finder not to display the .plist files. Probably something to do with hidden files.  You could try typing "Cmd Shift ." to toggle Finder's display of hidden files, but that may not be the issue.

You can view the .plist files in the Library/Preferences folder without Finder. Launch the Terminal app and copy/paste these commands, one at a time:

cd ~/Library/Preferences
ls *.plist
ls com.adobe.*.plist

[Rafael Aviles]

That was it, John, thank you very much! The Terminal commands showed the .plist file. Somehow my Finder is set to not show hidden files, I wonder how I managed that. Is there a Terminal command to set it back to show hidden files?

Also, is it safe to remove the com.adobe....plist.lockfile files?

[johnrellis]

@Rafael Aviles: "Is there a Terminal command to set it back to show hidden files?"

The Terminal command "defaults write com.apple.finder AppleShowAllFiles true" works on my Mac OS 26 test machine.

[johnrellis]

@Rafael Aviles: "is it safe to remove the com.adobe....plist.lockfile files?"

I think so. I wasn't even aware of them until your screenshot, and I don't recall ever seeing them.  Some of the google results indicate that Mac OS stopped using them years ago when it rearchitected how preferences work.  I would think if their last-modified dates show they're ancient, it's safe to delete them.

[wysiwygot]

It is as long as LR isn't running

[Rafael Aviles]

@johnrellis  Thank you very much, John, I really appreciate your help.

[Rafael Aviles]

@wysiwygot Thanks! 

[Matt Fitt]

Thank you, John, moving the catalog outside of OneDrive seems to have helped significantly.  

I'm still unclear as to the reason, since my LR catalog has been in that OneDrive folder for at least the last 6 months or so, and yet the problem only arose immediately after the latest update.

Again, thank you for your help.  

[saitejagopi2894]

@RlroodThanks for reaching out, and sorry to hear you're experiencing performance issues.

Could you please try purging the Adobe Camera Raw (ACR) cache and restarting your machine? This often helps improve performance.

To purge the cache:

1. Navigate to the following folder:
   C:\Users\<your-username>\AppData\Local\Adobe\CameraRaw
2. Delete the entire CameraRaw folder.

Additionally, please check your Windows Power Mode settings:

• Go to System → Power & Battery
• Under Power Mode, ensure it is set to Best Performance

Let us know if these steps help resolve the issue or if you continue to experience problems.

[saitejagopi2894]

Additionally, please check if the “Automatically write changes to XMP” option is enabled. If it is, kindly disable it and restart the application.

To check this setting:

1. Open Lightroom Classic
2. Go to Edit (on Windows) or Lightroom Classic (on macOS)
3. Select Catalog Settings
4. Navigate to the Metadata tab
5. Look for the option “Automatically write changes into XMP”
6. If it’s checked, uncheck it and restart Lightroom Classic
   
   

Disabling this option can help improve performance, especially when working with large catalogs.

Let us know if this helps or if you need further assistance!

[Florence_in_Switzerland]

Hi experiencing all the same lagging issues. My catalogue is on same drive as RAW files. No dropbox, onedrive issues here. I have unchecked the various boxes in catalogue settings as suggested before. Restarting LR and computer. The only change is that it seems working fine at first but a few minutes into it the lagging happens for everything I try to do in catalogue or develop module. 

Thanks.

[saitejagopi2894]

@Florence_in_Switzerland

Thanks for reporting the issue. To help us investigate further, could you please provide the following details?

1. Have you tried the steps mentioned above ?
2. Could you share your System Info? You can find it under Help > System Info in Lightroom Classic.
3. Which specific actions are causing lag? For example, does it happen when adjusting sliders like Exposure, switching between modules, or applying presets?
4. How many images in your catalog have Enhance edits applied (e.g., Denoise, Super Resolution)?
5. What’s the size of your catalog—both in terms of number of images and the catalog file size on disk?
6. Does disabling GPU acceleration and restarting Lightroom improve responsiveness? If yes, could you check whether your system is using the latest Studio drivers from your GPU vendor?

[Florence_in_Switzerland]

My previous reply seem to have disappeared and has not been addressed....here it is again. 

1. Yes I tried the steps mentioned above that applied to me, no change.

2. System info at the bottom 

3. Seems that the problems are mostly on images that have a substantial edit history and a number of masks, not many AI masks though. Adjusting sliders, comparing before and after, anything in develop module takes between 5-15 seconds to react. In grid module, comparing two images in compare view can take up to 20 seconds to load.

4. Very few of my images have denoise applied and none have super resolution.

5. 9'000 images in my catalogue. 620 GB of raw files stored on external drive together with the catalogue

6. I always have GPU accelaration off. This was recommended to me previously since my chip is quite old and not the most performing. It worked ok so far (not super fast but ok) before 15.0 was launched. I don't understand the second part of your comment regarding the latest sudio drivers. 

Thanks for your attention.

System info:

Lightroom Classic version: 15.0 [ 202510171722-44f87028 ]
License: Creative Cloud
Language setting: en
Operating system: Mac OS 15
Version: 15.6.1 [24G90]
Application architecture: x64
Logical processor count: 6
Processor speed: 3.1GHz
SqLite Version: 3.36.0
Built-in memory: 65,536.0 MB
Dedicated GPU memory used by Lightroom: 287.9MB / 4,096.0MB (7%)
Real memory available to Lightroom: 65,536.0 MB
Real memory used by Lightroom: 4,305.3 MB (6.5%)
Virtual memory used by Lightroom: 46,469.5 MB
Memory cache size: 2,175.5MB
Internal Camera Raw version: 18.0 [ 2389 ]
Maximum thread count used by Camera Raw: 4
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 2065MB / 32767MB (6%)
Camera Raw real memory: 2168MB / 65536MB (3%)

Cache1:
Final1- RAM:1,734.0MB, VRAM:0.0MB, ESC02899.ARW
NT- RAM:1,734.0MB, VRAM:0.0MB, Combined:1,734.0MB

Cache2:
m:2,175.5MB, n:253.8MB

U-main: 111.0MB

Standard Preview Size: 2880 pixels
Displays: 1) 4096x2304

Graphics Processor Info:
Metal: AMD Radeon Pro 575X
Init State: GPU for Image Processing supported by default
User Preference: Off
Enable HDR in Library: OFF
GPU for Preview Generation: Off (S3_4)

Application folder: /Applications/Adobe Lightroom Classic
Library Path: /Volumes/Extreme SSD/Lightroom/LR catalogue/Lightroom Catalog-v13-3.lrcat
Settings Folder: /Users/Florence/Library/Application Support/Adobe/Lightroom

Installed Plugins:
1) AdobeStock
2) Aperture/iPhoto Importer Plug-in
3) Flickr

Config.lua flags:

[johnrellis]

@Florence_in_Switzerland, can you confirm that you've disabled Catalog Settings > Metadata > Automatically Write Changes Into XMP?  

"I don't understand the second part of your comment regarding the latest studio drivers.:"

That only applies to Nvidia GPUs on Windows.

[Florence_in_Switzerland]

saitejagopi2894

Adobe staff seem to have left this topic entirely and left us without answers and a terrible experience with 15.0....

I took the time to answer your 6 questions in details and you never got back to me....

What are my options? 

[SergeiZ]

The best course of action is to roll back to the 14.5.1 in the adobe suite, click three dots when you see intalled applications and pick the previous version. Additonally, use help - provide feedback - inside lightroom itself to leeve you notes about your experience. You can use this email to talk them directly - photosup@adobe.com

Also, go on to adobe creative cloud webstie, help, start a help chat and demand to talk to a live person. Good luck 

[Florence_in_Switzerland]

saitejagopi2894 Can you please reply/comment on my previous post replying in details to all your questions....Thanks

[AxelMatt]

@Florence_in_Switzerland 

See @johnrellis post here: Gelöst: Re: LRCC 15 Slow? - Adobe Product Community - 15570529 ,

especially point 2 and 3.

[wysiwygot]

Since I'd nearly the same Problems as Florence_in_Switzerland.  Deleting the Camara Raw folder in Appdata/local was the boost on my system. Actually it behaves as with 14.x. Slider response and overall LR performance is acceptable.

Bevor deleting the CR Folder starting LR15 with a new catalog and importing all files from the 14.x catalog improved the performane in a reasonable way.

[Rlrood]

Have done everything mentioned in all the above posts except starting LR with a new catalog and importing all files from previous catalogs, and my app. is still limping alon. Definitely not acceptable. Are ther any specific step-by- step procedures for starting with a new catalog? Thanks to all.

[Rlrood]

Thanks, have done all of the various things suggested in this thread and LR is NOT working. After a restart it might act normally but during the middle of editing the first image about halfway through the slowdown begins, slow sliders to the point of not "sliding" at all, etc. Master catalog is 2.27 GB and 251,333 files. Should mention that the about a year ago I moved the catalog, etc. from C drive (SSD) to a  fast internal hard drive. Did this because C drive was filling up. Expected a LR slowdown from the move but it has been working fine untill V15 came along. 

Sitting here now with a large number of  files to process and can not do it, really need help!!!

[AxelMatt]

@Rlrood 

Please take a look @johnrellis post here: Gelöst: Re: LRCC 15 Slow? - Adobe Product Community - 15570529

Especially point 2 and 3.

[Rlrood]

Thanks, have done everything in the referenced post and no improvement. 

[Rafael Aviles]

I am beyond frustrated. After trying every single possible fix recommended in this thread by several experts, the problem persists. LRC V15 is unuseable and unpredictable. Some times it works fine for a few minutes, then it becomes slow and unresponsive. Other times the problem occurs almost from the beginning. The Activity Monitor (macOS) shows LRC is using close to 200% of the CPU!

I am beginning to thing that the culprit is the Culling feature, even though I have it turned off. Somehow LRC must be sneakily culling thousands of photos at the same time I'm trying to do other things. I dont sync my photos to the cloud either, so I don't know what else LRC could be doing in the background that uses so much CPU and brings thing to a crawl. I wish Adobe did something about it!