Copy/Paste Masking will cause system to freeze

[Jillian271525787u5h]

Hi!

I have been having an issue since the last update where when I copy a mask and then attempt to paste it 5+ times, the entire app will freeze and I will have to restart it to be able to click anything. This is frustrating as I just bought a really intense Macbook to make sure my editing (M4 Pro 48 GB memory) was quick and seamless. Crazy that what is seemingly a bug is getting in my way. Does anyone know how to resolve this? 

Version of the app

• 9.0

Platform and OS version

• M4 Pro, Sequoia 15.6.1

Basic steps to reproduce the problem

• Copy mask and paste it 5+ times, sometimes it will take 10+ times

Expected result and actual result

• Expected result is for system not to freeze

Thank you!

Jillian

[nikunj.m]

Hi, we're sorry about the trouble and about the delay in responding. 

Are you still experiencing this behavior? If yes, please go to the Help menu in Lightroom Classic, then System Info, and copy the text. You can share the info with us by either pasting it as a reply here or in a text file and sharing the file with us.

Meanwhile, you can check if Lightroom is added to Full Disk Access on your Mac using the steps here: https://adobe.ly/3XaEb3S

Also, try updating macOS to the latest version of macOS Sequoia (15.7.2).

Thanks,
Nikunj

[Jillian271525787u5h]

Hi Nikunj!

Thank you for your response, I was worried that this would just be forgotten. I am still expereincing this issue. My Mac is now fully updated, and I have ensured Full Disk Access. Here is that system info:

Lightroom version: 9.0 arm64 [ 20251017-1944-414afc8 ] (Oct 17 2025)
NGL Version: 1.42.0.5
WF Version: 8.0 58cbd19
VF Version: 1.0.164
HIL Version: 40501
CAI Version: c2pa-c/0.6.0 c2pa-rs/0.46.0
PH Version: 5.2.3
Adobe GSDK Version: 1.4.0.42
CR Version: 29.5.0.202509162212_6e7a997

Operating system: macOS
OS Version: macOS 26.1 (25B78)
Application architecture: arm64
Computer model: Mac16,7 / Apple M4 Pro
Logical processor count: 14
Real memory available to Lightroom: 49,152.0 MB
Real memory used by Lightroom: 2,368.0 MB (4.8%)
Peak memory used by Lightroom: 2,369.0 MB
Memory cache size: 671.6 MB

Internal Camera Raw version: 18.0 [ 2389 ]
Maximum thread count used by Camera Raw: 8
Camera Raw SIMD optimization: Neon
Camera Raw virtual memory: 613MB / 22528MB (2%)

Display: 3456x2234

Graphics Processor Info: Metal: Apple M4 Pro
Graphics Processor Detail: loaded: Yes, supported: Yes, compute: Yes, init: I4_GPU4, hard: success, soft: success, al: Yes, dl: No
OS Media Capability: true

Application Folder: /Applications/Adobe Lightroom CC
Settings Folder: /Users/jillianhuels/Library/Application Support/Adobe/Lightroom CC
Library Folder: /Users/jillianhuels/Pictures/Lightroom Library.lrlibrary

Let me know if you have any recommendations. Thank you!

[Aleke]

Hi @Jillian271525787u5h, thanks for sharing your System Info!
Did these issues start after updating to macOS 26? At the moment, Lightroom hasn’t been fully cleared for compatibility with macOS 26, which could cause some unexpected behavior.
Also, could you clarify what you mean by “Copy mask and paste it 5+ times”? Are you batch-pasting the mask settings to multiple photos? So far we haven't been able to reproduce this issue. If you can share a screen recording of what’s happening, that would be super helpful.
Thanks!
Alek

[Jillian271525787u5h · Accepted solution]

Hi Aleke! I attempted to re-create the freeze and it seems like the issue has resolved. Super weird. I am wondering if it was a specific set of photos that caused the issue. I would create a radial mask with increased exposure and decreased clarity, copy the mask, and then paste it across multiple pictures. Sometimes even after just the third paste, the entire system would freeze. I couldn't click or do anything. I tried to wait it out once to see if it would give me a crash report like the app does sometimes but it never did. If it happens again, I will paste a video into this thread, but for the meantime, it seems like it has resolved. 

[Jillian271525787u5h]

Hi @Aleke and @nikunj.m ! I was able to re-create the issue and capture it on video. The system had just frozen, so I quit the system and restarted it. Then I began the recording. It only let me paste the mask twice before the system froze. It doesn't look like it is responding when it freezes. Let me know if you have any ideas! Here is a link to the recording: https://drive.google.com/file/d/14JtO2iURMqtl6-TDqIurGKN4-jG8PN21/view?usp=sharing

[Srishti Bali]

Hi @Jillian271525787u5h

Thank you for sharing the detailed information and the video recording. As Alek mentioned, multiple users have reported performance issues on macOS Tahoe, and it is not yet fully supported by the current Lightroom versions. Please try the following steps and let us know if it helps:

1. Update Lightroom to the latest version (9.1).

2. Reset Lightroom preferences by launching the app while holding Shift + Alt, then confirm Reset Preferences when prompted.

Regards,

Srishti