Horizontal dotted line across screen

After opening applications I will sometimes see dotted lines across the screen that line up with horizontal border lines in that application. Normally it is only one or two lines. If for instance I open a whonix browser dvm, there will be a dotted line lined up with the border directly under the address bar. It extends past the window, across the screen to the edge of the screen. Sometimes one towards the bottom of the window if there is a border line there too. Such as the one for the starting page /usr/share/doc/homepage/whonix-welcome-page/whonix.html
If I move the app window or click anything such as the address bar, the lines will disappear. Sometimes they return later. I see this with other apps too but the lines will vary in location due to app window size and layout.
I have seen some older pages on similar dotted lines in search results that mention hardware or driver issues. From what I have read, if the lines were always present or did not move, then it could be a hardware issue such as the screen itself.
I know this may not be Qubes specific but I have only encountered it while using Qubes. Has anyone else experienced this or does anyone happen to know what I should check to possibly resolve the issue?

Hi @ChiselTip!

Your post reminded me of a comment someone made that accurately predicted some graphical artifacts on my LUKS unlock screen. From skimming through the forum I believe those might be a distinct known-issue than the lines you describe, but some folks also report lines that could be similar to yours?

I don’t have any insight into what might be causing them, but I’ve seen troubleshooting steps in some of the posts I found by searchimg for “artifact”:



Thank you, I will use that search and see what all I find. So far, it has not affected my work, but I do hope to find what may be causing it.

I did not find anything in the artifacts search results that was similar to this. I took two screenshots of the lines and was going to crop them and remove metadata so I could share them here. I then found out two things. None of the image viewing apps included with Qubes offer a way to crop the images, and the dotted lines outside the app window are not present in the screenshots. I am curious why the lines outside the app window do not show up in screenshots yet the ones within do.

The lines are present within the window in the screenshots and one could imagine what it looks like with the line extending past the window. However, paranoid or not, I still need to crop them and remove data before I would be willing to upload them.
I’ve removed as much metadata as I could already. Any suggestions for image viewing software that allow editing/cropping the images?

Until I am able to do that, I will try to explain the dotted lines a little better. If the app in use is a browser, the lines are roughly the same thickness as the border or dividing line under your address bar. The dots or spaces between the dots are not much bigger than that thickness as well. If seen when using a browser app, the line most seen will be inline with that border or dividing line mentioned, and extend all the way to the edge of the screen. If you drag the window around, the line will move with the window, as if part of it.

Depending on your level of comfort with command line tools, I am pretty sure that ImageMagick is available in at least some of the default templates. (Typically under the command convert. If which convert prints something, ImageMagick is installed.)

It is a fairly comprehensive tool, and I’d suggest searching for help around both: “removing metadata” and “optimizing images” using ImageMagick. (Often the steps taken to optimize the loading time of images for web applications involve removing most metadata.)
StackOverflow answers are usually a good source of inspiration for ImageMagick usage.

Again, it is a command-line-only tool, and the usual recommendations of working in a disposable qube (dispVM) and understanding the commands before running them apply.

As an additional warning, the vast majority of software that deals with images is prone to security vulnerabilities (image formats are often very complex): ImageMagick is no exception. Work in a dispVM!

All that being said, if you took screenshots from dom0, those images are safer to work with. :slightly_smiling_face:

Always mindful of what I share

“We kill people based on metadata.”
General Michael Hayden

I have the same problem. But if I use PrtSc to capture the image, it won’t show up in the image.

There’s one way to reproduce this:

  1. Open TBB in a whonix dvm.
  2. Press Ctrl+L.
  3. Press Tab 3 times.
    You’ll see that line.

Also reproducible on the “Settings” page, with plain Firefox running inside debian-11-dvm.

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What GPU are you using?

I was able to capture an image where the line does show up, but I’m not sure it will if I upload it. I will try to upload it here later. Something else I noticed, if I open that image with ImageMagick, the line will then extend out of that window to the edges of the screen again. And it will move with the ImageMagick window if I drag it.

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Integrated, UHD 630

Really really weird. Maybe a gui stack bug.

Hypothesis about why screenshots don't always show the dotted lines

I might be wrong, but I believe that the screenshot utility does work off the rendering engine and actually creates a fresh rendering of the screen to a file. (Instead of “taking a picture of the screen” as we usually think about it.)

If that was the case, it may explain why the rendering defaults don’t show up in the screenshots: the context being different, the conditions necessary to produce those defects may not be present.

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That makes senses, I didn’t have the words but thought it may be something like that. On the ones I have taken, sometimes the lines will still be evident inside the app window but not outside of it. This may be due to background and contrast, I think.

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Well, it doesn’t seem to matter what I use, or how I try to do so, I have been unable to upload any images. I thought it might be too large so I tried multiple different ones. I’ve left it processing for hours and it never finishes.

I didn’t see this in my previous searches but found it today. This is almost identical to what the lines look like and how they line up with other lines or borders within a window.


Unfortunately, the suggested inversion artifacts don’t fit what I am seeing or what is seen in that post. What I have seen with inversion artifacts on monitors, normally resembles more of a grid and affects the whole screen.
If I hook the monitor up to any other device or use it with an OS other than Qubes, I don’t experience the dotted line.