Side bar disappearing

Hi ​@Srishti Bali, 

thank you for looking into it.
1 - the sidebar disappear after few minutes WITHOUT defined actions as far ass I can see
2 - yes, restarting Lr restore the sidebar (and the masks handling 

)

3 - 
 

Lightroom version: 9.5 arm64 [ 20260728-0500-db8bf00 ] (Jul 27 2026)
NGL Version: 1.43.0.5
WF Version: 8.5 20b9f90
VF Version: 1.0.164
HIL Version: 40501
CAI Version: adobe_api/1.66.1
PH Version: 6.1.1
Adobe GSDK Version: 1.4.0.213
CR Version: 29.5.0.202509162212_6e7a997
Catalog ID: 0eab27ecd9f645059e5621ca0636f7ab

Operating system: macOS
OS Version: macOS 26.5.2 (25F84)
Application architecture: arm64
Computer model: MacBookAir10,1 / Apple M1
Logical processor count: 8
Real memory available to Lightroom: 16.384,0 MB
Real memory used by Lightroom: 841,0 MB (5,1%)
Peak memory used by Lightroom: 3.929,0 MB
Memory cache size: 3.839,7 MB

Internal Camera Raw version: 18.5 [ 2673 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: Neon
Camera Raw virtual memory: 21MB / 6144MB (0%)

Display: 2880x1800
Dark Mode: Yes

Graphics Processor Info: Metal: Apple M1
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/bmz/Library/Application Support/Adobe/Lightroom CC
Library Folder: /Users/bmz/Pictures/Lightroom Library.lrlibrary
4 - I’ll try but I don’t know the exact moment

Hi ​@biemmezeta 

Thanks for reaching out, and I'm sorry you're experiencing this issue. To help us investigate, could you please provide a few more details?

• Does the sidebar disappear consistently after a few minutes, or does it happen only after performing certain actions?
• Does restarting Lightroom temporarily restore the sidebar?
• Could you share your System Info? (Go to Help > System Info, click Copy, and paste the details here.)
• If possible, could you share a short screen recording/ or screenshot of full screen showing the sidebar turning into a solid gray rectangle? That would help us better understand the behavior.

In the meantime, I'd suggest resetting Lightroom preferences. To do this, press and hold Shift + Option (macOS) or Shift + Alt (Windows) while launching Lightroom, then let us know if that makes any difference.

Looking forward to your reply.