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Participating Frequently
February 13, 2025

P: Brush Mask creates an errant diagonal straight line stroke (Win)

  • February 13, 2025
  • 19 replies
  • 3846 views

Lightroom Brush Option is drawing a weird line when I start to select an area. This won't stop happening. I've closed and open the program numberous times. Updated masks and AI features constantly and it's still happening.  I can't use the brush option at all and I am on a deadline. I don't know how much longer I can keep using Lightroom or my subscription. 

19 replies

Participant
May 11, 2025

Same here, starte happening after update and happens each time when using Brush tool, just draws overlay from top left corner, if zoomed it will draw it from top left of zoomed screen, not through whole pic. I have to click once the and then click again to prevent line from appearing or just delete kt after i finish selection, really annoying but hey

Participant
April 25, 2025

Did you ever find a solution to this problem? It's been happening to me for a couple months now, best way I could find avoid it is to click first rather than click & hold.

Rob_Cullen
Community Expert
Community Expert
April 26, 2025

The problem exists. I saw it once very briefly after reading your posts, but never again.

Sorry I don't have an answer. I have a new mouse- so could be mouse related.

 

Regards. My System: Windows-11, Lightroom-Classic 15.1.1, Photoshop 27.3.1, ACR 18.1.1, Lightroom 9.0, Lr-iOS 10.4.0, Bridge 16.0.2 .
Known Participant
May 2, 2025

It's definitely not mouse-related. If you haven't yet, I'd recommend trying it on a lower-power system (and maybe one with DPI scaling by default, though I'm not positive this is a factor), such as a laptop. It seems to be performance related, as there's consistently a small freeze whenever I encounter the issue. My laptop is by no means "low power", but it's almost certainly more limited in resources than your average desktop built for editing.

Participating Frequently
April 1, 2025

Apologies to the community. I've bever used the help feature before and didn't realize it was bringing me to a LR discussion forum and not LR customer service? Oops. Oh well, lesson learned. Thank you to those who've added productive assistance/suggestions! 

Rob_Cullen
Community Expert
Community Expert
April 2, 2025

Hi Kelly, FYI, To chat with an Adobe Support person-

Contact adobe support by clicking here, https://helpx.adobe.com/contact.html?rghtup=autoOpen
In the chat field (lower right of screen), Typing “Agent” into the chat text field will bypass the initial chatbot.
be patient, it can take quite a while to reach a human
If you are not able to get to the chat window, then disable your ad-blockers, firewall, enable cookies/scripts on your browser. If it still fails then change your browser/machine/network.


Regards. My System: Windows-11, Lightroom-Classic 15.1.1, Photoshop 27.3.1, ACR 18.1.1, Lightroom 9.0, Lr-iOS 10.4.0, Bridge 16.0.2 .
Participant
April 21, 2025

I am having the same issue.

Rob_Cullen
Community Expert
Community Expert
March 31, 2025

@Eager_nature2432  and @Generous_view0D45   Sorry but I don't have the answer. This problem is something I have never encountered or seen in posts by others except yourselves.

Making some guesses here with common suggestions for things you might try (if not done already)-  A Preferences reset, or a full un-install and re-install.

 

Regards. My System: Windows-11, Lightroom-Classic 15.1.1, Photoshop 27.3.1, ACR 18.1.1, Lightroom 9.0, Lr-iOS 10.4.0, Bridge 16.0.2 .
Inspiring
May 11, 2025

This has been reported before (see Re: Issues with Lightroom masking brush - Adobe Community - 15208589 for one), and I see the same problem on two different PCs with different processors and GPUs so I don't think it's a driver issue. Neither do I think it is user error - I am not using shift-click when it happens.

 

As others have said it is possible to overcome the problem by deleting the mask and trying again, perhaps two or three times - but it is very irritating, and breaks the workflow. I try to avoid using brush selections now, but I shouldn't have to.

 

I do hope Adobe will acknowledge this problem and investigate it.

Participant
March 28, 2025

This is unnaceptable! I have been using lightroom for over 3 years. You guys did an update a month ago and the entite platform is completely useless. I go to use the brush tool, it automatically makes a line across the screen that I have to delete and start over. I go to use the bandaid tool, it automatically begins making random bandaid selections and I have to delete up to 5 in less then a minute... A complete waste of time. The linier grid tool stalls too and I have to redo it 3 entire times or more. The slide buttons on the right tool bar all get stuck or when I move them they go right back to the middle and I have to do it over and over again. I pay over 30$ a month for this? Please fix this! Or please give me some sort of reimbursment because this is absolutely useless. 

Rikk Flohr_Photography
Community Manager
Community Manager
March 28, 2025

From the description of the problem, it sounds like you:

 

1. Have an out-of-date video driver

2. Mouse/Tablet Driver

3. Or both 

Recommendations: 

1. Update your OS to the latest version available from Microsoft

2. Go to your GPU manufacturer's website and install the latest Studio Driver - not their Gaming Driver

3. Make sure all of your pointer devices (Mouse, Tablet, Track Pad, etc) are up to date from their respective manufacturers site.

 

If after all this, you still are seeing the same issue, reset your Lightroom Desktop Preferences. 

This procedure works for both Lightroom Classic and Lightroom Desktop.

If you are using Lightroom Desktop, it can change your local storage location. Please review this setting after resetting preferences. 

 

Reset Procedure:

1. Close Lightroom.

2. Hold down [Alt/Opt]+[Shift] while restarting Lightroom.

3. Overwrite the Preferences when prompted by the dialog.

4. Close Lightroom.

5. Restart Lightroom.

 

If that fails to correct the problem, then you will need to supply complete system information in your reply. 

 

My money is on your GPU driver...

 

 

Rikk Flohr: Adobe Photography Org
Participant
March 28, 2025
I had to uninstall the newest update & downgrade. The new update is loaded
with bugs. None of your options worked. Thanks.
Rob_Cullen
Community Expert
Community Expert
March 19, 2025

@Eager_nature2432  Your line looks like a red Brush overlay where a straight line has been drawn by the procedure-

Click Brush > move cursor > Shift+Click Brush.

It is useful to check the box for [Reset Sliders Automatically]. This could eliminate a problem such as the brush beeing set to a color that keeps appearing.

Does the coloured line disappear when you press keyboard [ O ] for Overlay?

 

 

Regards. My System: Windows-11, Lightroom-Classic 15.1.1, Photoshop 27.3.1, ACR 18.1.1, Lightroom 9.0, Lr-iOS 10.4.0, Bridge 16.0.2 .
Participant
March 25, 2025

Hi again, 

 

I have screen recorded the issue. I do not select shift when using the brush, when i make my intial click the straight line generates. I delete the mask or undo and try again until it stops doing it. 

 

 

Participating Frequently
April 1, 2025

Thank you for taking the time to help with this! Yes, that's the only way I've been able to resolve it to, but it's often taking 5-6 tries and that is a lot of valuable time. Hopefully I can reach out to LR? and see about a fix as it sounds like this is an issue for many users. 

Rob_Cullen
Community Expert
Community Expert
March 16, 2025

Post a screen-clip of the "weird line" and someone may be able to suggest an answer.

 

 

Regards. My System: Windows-11, Lightroom-Classic 15.1.1, Photoshop 27.3.1, ACR 18.1.1, Lightroom 9.0, Lr-iOS 10.4.0, Bridge 16.0.2 .
Participant
March 19, 2025

Hi, 

 

I am having the same issue. When I click to mark the area with the brush it makes a diagonal line from the click point, which I later have to subtract. I am zoomed in on the photo whilst completing this work. 

 

Participant
March 19, 2025

I'm having the exact same issue, its been happening for a month now at least? Whenever I go to make a mask with a brush, it first creates that weird bugged straight line from the top left. Then I undo it, go to make an another mask, sometimes it does it AGAIN and sometimes works fine. But, then I also get a thing where I click on the brush at this point to try it again, and it creates a layer that already has a lot of settings turned on...those settings just get put to that brush layer instantly and they dont seem to make any sense? Im adding a leyer and then the brush just does a bright blue or super over exposed layer instead of the normal masking red, it's so weird. So then I undo that one also, and then third or 4th time, I can finally use the brush mask tool to make something proper.
I use it on PC and have a wacom tablet, which I thought was initially causing it but Im not sure?

Participant
March 13, 2025

Hello,

After updating Lightroom I am having trouble with the masking brush. On the first stroke of a new mask it creates a long line extending to the edge of the picture that I didn't do. Following this first stroke I can precisely add another stroke where I want it e.g under the eyes only to remove shadows. But when I add a new mask with the brush, it repeats this issue.... HELP!!

thanks!

KR Seals
Community Expert
Community Expert
May 6, 2025

On reading this post, I decided to try it on my Win11 PC. I'm still on V 8.2. 

The very first time I tried a mask with a brush, once I touched the brush down on the upper left corner of the image, a long brush stroke was made perfectly horizontal to the othere edge of the image. Same size as the brush. The second brush application in the same image was normal. I tried a few different images and the mask with brush strokes was also perfectly normal. I closed the app and tried again. Every thing worked normally. So, I only saw it that one, very first brush application.

 

Ken Seals - Nikon Z 9, Z 8, 14mm-800mm. Computer Win 11 Pro, I7-14700K, 64GB, RTX3070TI. Travel machine: 2021 MacBook Pro M1 MAX 64GB. All Adobe apps.
Participant
February 13, 2025

Lr version 8.2 updated today 2/13/25

Rikk Flohr_Photography
Community Manager
Community Manager
February 13, 2025

I am unable to replicate this failure using the instructions provided. 

Likely culprits would be any pointing device drivers and GPU updates that may need updating. 

Rikk Flohr: Adobe Photography Org