User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0

Steps to reproduce:

1. Visit https://github.com/search?q=a
2. Click CTRL+SHIFT+S

This is a regression with recent nightly builds (102.x, reproducible in build 20220530093943). Not reproducible in neither beta nor stable.

Actual results:

Page goes gray and all content is hidden.
Taking a screenshot still works properly however it's difficult to select what to screenshot when you can't see stuff.

Expected results:

Page should show normally.

Same behavior on Bugzilla itself.

P.S. don't file bugs in Core::General, Firefox::Untriaged should be the starting point unless you already know the right product/component

[Tracking Requested - why for this release]: screenshot feature is broken on multiple websites.

Currently trying to find what regressed this.

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=0d8f25c4388af0894425506e71024044f4d3402a&tochange=f0c4c97a8e6aa34214f287cb499321b6a0186c2f

And it was already on file :-(