User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0 Build ID: 20180406103336 Steps to reproduce: With WebRender enabled use UI features like right click menu, autoscroll (middle mouse button) or drag tabs. Actual results: Maximized window: A grey overlay appears that extends from the left side of the browser window to the point where the UI action is displayed. So if you use autoscroll, the grey overlay reaches from the left of the browser window to the right side of the overlay icon. Windowed mode: The whole window shows a grey overlay. Expected results: No overlay appears.

This doesn't happen on every page. It's very noticeable here with autoscroll: https://www.forum-3dcenter.org/vbulletin/

Another good example: https://www.onlinekosten.de/forum/index.php A light _blue_ overlay when using autoscroll.

Can you attach a screenshot? Do you have another machine you can try to reproduce this on, and does it reproduce there?

I can't reproduce this anymore. Seems to have been fixed in the meantime.

I can reproduce this now on a machine with an Intel HD 630 on the two websites I mentioned before. The overlay isn't visible on screenshots. I'll try to get a good picture with an actual camera later.

The weird thing is id doesn't happen on my old machines, where I had this behaviour before. It happens only on a new machine, running the same Nightly build. So it doesn't seem to depend on a specific WebRender version but on some other external factor I haven't identified yet.

With today's build the issue is gone again. I tried to find the regression range, but all builds work correctly now. So again this points to some external factor. I also experience better performance and less correctness issues with WebRender now that the issue is gone.

P3 until somebody can reproduce it reliably.

(In reply to TMart from comment #5) > I can reproduce this now on a machine with an Intel HD 630 on the two websites I mentioned before. I couldn't reproduce so far, neither with older Nightlies. (The only thing I found out was that disabling ANGLE was a total catastrophe: When changing window size, the existing content is simply scaled/squashed. Recent builds mostly do not show text and images at all. Everything flickers. But with ANGLE everything seems fine.) I have: > Description Intel(R) HD Graphics 630 > Vendor ID 0x8086 > Device ID 0x5912 > Driver Version 24.20.100.6025 > Driver Date 4-25-2018

Since this has only ever been reported again Intel, I'm moving to definitely not block the nvidia release.