User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:75.0) Gecko/20100101 Firefox/75.0

Steps to reproduce:

I visited a page which had a cloudflare delay page.

Actual results:

It contained three dots which would flicker and strobe. I wasn't able to inspect it-- escape didn't work-- but I think this is the script for it.

https://ajax.cloudflare.com/cdn-cgi/scripts/7089c43e/cloudflare-static/rocket-loader.min.js

Expected results:

It shouldn't have flickered or strobed.

Resetting severity to default of --.

P.S. Disabling hardware acceleration seems to solve this.

HI,

Can you please provide the page you visited? Also, would you mind including a video as well? SO I can try to replicate on my end.

Thanks

Best,

Clara

Page: https://www.compassgames.com/red-star-white-eagle-the-russo-polish-war-1920-designer-signature-edition.html

I can't do video.

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Hi,

I am not able to replicate the issue. I've tried on both mac Os 10.14 and windows 10 pro.

On the following versions:
Release 76.0 (64-bit)
Beta 77.0b8 (64-bit)
Firefox Nightly 78.0a1 (2020-05-27) (64-bit)

Please test if the issue occurs to you in safe mode (add-ons disabled). Here is a link that can help you do that:
https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

If the issue persists, also test it using a fresh profile, you can find the steps to do that below:
https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles?redirectlocale=en-US&redirectslug=Managing-profiles#w_starting-the-profile-manager

Also, try this on the latest version of nightly. You can download it from here: https://nightly.mozilla.org/

I will move this over to a component so developers can take a look over it. If is not the correct component please feel free to change it to an appropriate one.

Thanks for the report.

Best regards, Clara.

I have a strobe sensitivity and visual motion sensitivity and can't safely use Firefox or any other browser without safety fixes. ""safe" mode" and "fresh profiles" aren't safe for me.

Hi Marja, can you navigate to "about:support" and attach the information from there so we can get more information on your graphics configuration? Also, make sure you have restored the configuration that was causing the issue when you collect that "about:support" information, because we'd like to be able to see what potential codepaths are leading to the issue.

I do not see any flickering in the loading animation on my Mac either.

A video would really help.

I can't get through the screen recording menu on the Mac. If you have another way to take a video, preferably one which doesn't involve too much injury from the strobe, please share.

(In reply to MarjaE from comment #12)

I can't get through the screen recording menu on the Mac. If you have another way to take a video, preferably one which doesn't involve too much injury from the strobe, please share.

It's a bit low tech, but maybe a phone camera video, or webcam? It depends on whether your camera records at high enough frame rate to show the strobing, but it might. Do you have anyone who could assist you to take this video without putting yourself at risk?

(In reply to MarjaE from comment #12)

I can't get through the screen recording menu on the Mac. If you have another way to take a video, preferably one which doesn't involve too much injury from the strobe, please share.

I only know of Cmd+Shift+5, or through the menu in the QuickTime app (which I believe ends up in the same UI). I can't assess how much strobing occurs on those UIs. As for the loading animation on cloudflare itself... I'm not sure. Presumably it always shows up in the same place on the screen, so maybe it can be covered up during the animation. But please don't risk injury just to get the video.

(In reply to MarjaE from comment #0)
Does this bug still occur?

Not on that site.