On Discourse when I want to comment I get that the textarea and the preview are transparent, also the button to sent the comment it is. I checked also with the inspector and all the elements has the background-color attribute so maybe is an issue on detecting what is the background color.

Do you have a specific URL on which you see this? It would help us in reproducing the problem. Thanks!

Yes of course, this happen on https://discourse.mozilla-community.org/t/have-you-tested-webrender/16137

This seems to be working fine now for me on the latest Nightly on OS X with webrender enabled. Can you confirm this is fixed, or are you still seeing the problem?

The problem persist and as in the screenshot happen also on Bugzilla and use the theme color that I am using on Firefox. The cool part that the Firefox screenshot feature doesn't show the problem but the right rendering.

Hm, interesting. Which theme do you have installed? I tried setting a theme and still get the correct (white) background on discourse.mozilla.org.

Now I am using https://addons.mozilla.org/en-US/firefox/addon/a-web-browser-renaissance/ but when i opened the ticket I was using https://addons.mozilla.org/en-US/firefox/addon/firetail/

I enabled the "a web browser renaissance" theme and still not able to reproduce it. Tried on Linux, OS X, and Windows. What window manager are you using on Linux? And do you have any non-Linux machines you can try it on? I'm wondering if this is specific to non-compositing window managers on Linux; we've had issues with those in the past.

I tried right now on my developer edition instead nightly on the same computer and the problem doesn't happen.

This is the about:support stuff of dev edition

Your two aboutsupport attachemnts are basically identical - they're both from the same Firefox version and buildid, and they both have webrender disabled. Can you confirm that you actually have WebRender enabled when you see this problem? Note that WebRender is not available in dev edition so if this is a WebRender-specific problem then it's not suprising that it doesn't happen in dev edition.

Seems that I uploaded the wrong about support of dev edition -.-' This is the right one, and for the nightly I generated that with the flag disabled.

Ok, well, I still need confirmation from you that this is only happening with WebRender enabled. Otherwise this bug is misfiled and we're barking up the wrong tree. Assuming it is, please also let me know which window manager you are using.

I enabled WebRender that generate the error during the previous screenshots. I am using KDE on Debian Sid with nVidia driver.

(In reply to Daniele "Mte90" Scasciafratte from comment #16) > I enabled WebRender that generate the error during the previous screenshots. > I am using KDE on Debian Sid with nVidia driver. WFM. It is very confusing that * you have so many addons that could break something (attachment 8923549 [details]), * WebRender is not manually enabled in your Nightly (attachment 8923787 [details]), and that * you uploaded something from devedition (attachment 8923788 [details],attachment 8923818 [details]; WebRender is only included in Nightly). I'm using Nightly 58 x64 20171030103605 de_DE @ Debian Testing (KDE, Radeon RX480) and I do not have these problems. https://wiki.debian.org/DebianTesting#How_Debian_Testing_Works If you really had WebRender enabled and saw this issue, I would suspect Debian Unstable (Sid) is broken in some way and it hasn't reached my therefore :) or you have a driver issue. Especially if you had a driver issue, raw data from about:support would be helpful (I think). WebRender would also tell if it was enabled and if it couldn't start because of problems or if it crashed. Maybe someone else also has this issue. Here are steps to verify: 1. Please create a fresh profile on about:profiles, for example, call it "freshprofile" 2. Download a fresh Nightly from https://nightly.mozilla.org 3. Then run something like ~/Downloads/firefox/firefox -P freshprofile 4. Open about:config an set layers.acceleration.force-enabled;true and gfx.webrender.enabled;true. 5. Then close Nightly and run that command again to start Nightly. 6. Please check if you see this issue on discourse and bugzilla. If it's fine, try it with one of those two themes or customize your UI, but note exactly all steps you've done. 7. Go on about:support, click on the raw data button and upload it as attachment here.

I tried with the same profile of the dev edition on nightly and there are no issue. I am trying to understand what is the file or settings that can be involved.

I tried with less few options on my pref.js and with disabling extensions and next re-enabling and now seems that everything is fixed. Maybe was something strange but now is working everything (finally)!