It just occurred again. I took a look at the display metrics, but none of the values are significantly different from metrics in the screenshot I previously sent you.

It happened while I switched from the shard map to one of my own rooms (W19N24). Note that the bug affects all rooms including the rooms of others. It also affects the replays (see screenshot below).

I didn't get the exact tick that happened, but the bug started around tick 586700. I also tried to trigger the bug again by looking at the replays, but that didn't provide any results.

Sure! I will give that a shot when it happens again!

1. OS is Windows 10. GPU is NVIDIA GeForce GTX 1050
2. Display drivers as in the drivers for my GPU? If so, yes I updated those a few days ago to the latest version (but it didn't have any effect on the issue)
3. I cannot confirm that, because I don't use the web version often, but the few times I did use it I did not have any issues.
4. 

Hi everyone! Since I have started playing Screeps I occasionally get some odd visual bug. I was wondering if anyone knows how to deal with this bug.

• What happened?

From time to time the lighting in all rooms breaks and at the same time slowly rotating yellow planes show up in rooms with turrets. See also these examples:

These yellow planes seem to be rotating around the location that turrets are placed (the turrets itself are invisible). Also, when a turret suddenly rotates (for example when repairing something), then the plane also rotates.

Restarting the game fixes the issue for a while, but this isn't a feasible permanent fix.

I already tried reinstalling the game and I also recently upgraded the driver of my graphics card. However, these things did not have any effects on the issue.

Making any change to the WebGL renderer changes the behaviour of the issue (although most settings make it worse). Changing the renderer to the legacy SVG renderer fixes the issue (but everything looks far less pretty). So it seems to be an issue with WebGL.

• What should have happened?
  Normal lighting behaviour and no rotating yellow planes.
• How can we reproduce this?
  Unfortunately I don't know. It just happens occasionally when I am playing the game. I also do not think that it happens after a fixed amount of time has passed
• Which shard is affected?
  It happened on both Shard 3 and on my private server. I don't know about the other shards. For me it only happened within the steam client. However, someone else on Slack also reported that it has happened to him in the browser.