[ExtraFPS] New NaN issue on Extra FPS

[canny[bot]]

• Login to http://maps.secondlife.com/secondlife/By%20Design/114/91/22 on Extra FPS build https://releasenotes.secondlife.com/viewer/7.1.11.11074622243.html

• You should be using the shared environment

• Observe the scene renders correctly

• Teleport to http://maps.secondlife.com/secondlife/Griffer%20Cove/51/45/24

• Observe the scene renders correctly

• Teleport back to the first location: http://maps.secondlife.com/secondlife/By%20Design/114/91/22

Observed Behaviour

• Immediately after teleport back to By Design, the scene renders correctly.

• After a few second, the scene changes to black & white & starts to flash.

• The scene renders as if it's hiting a NaN

• Occasionally the scene starts to render correctly again after a few more seconds, but usually the scene rendering remains broken.

• If you fail to reproduce this or the scene starts to render correctly, just teleport back to Griffer Cove then back to By Design & the scene is likely to stay broken.

• Repro Video1: https://i.gyazo.com/a72b7622c6dd5a6a9dcb64409e587c39.mp4

• Repro video 2: https://i.gyazo.com/edea29a220477b3f4a98d7fcb70063fe.mp4

• Videos taken on Ultra graphics

• Dan & Atlas also reproduced this bug on their systems.

• Does not reproduce on Delta FPS: Second Life Release 7.1.10.10800445603 (64bit)

https://secondlife.canny.io/admin/board/bug-reports/p/new-nan-issue-on-extra-fps

[canny[bot]]

This issue has been linked to a Canny post: New NaN issue on Extra FPS :tada:

[Whirly-Fizzle]

Might be the same bug as https://github.com/secondlife/viewer/issues/2656

[Geenz]

I can no longer reproduce this on 7.1.11.242970827.

[igorlproductengine]

Passed QA.

Verified on the Second Life Release 7.1.11.11469579464 (64bit) on Win10/OSX in the scope of https://github.com/secondlife/iqa/issues/374.