As a step in Yellow Screen of Death investigation (bug 1675823) we added a telemetry probe that captures all network I/O errors from our UI resource loads.

This is a very wide net that returns a large volume of bad resource loads.
Many of them may lead us deeper into our stack and look for intermittent and hard to reproduce problems that affect user experience (such as YSOD).

But as a side effect, we are getting a chance to review network loads that are bugs unrelated to YSOD, like popular bad settings, or mistakes that the parser is later hiding.

We'll use this bug as a counterpart to bug 1675823 to collect dependency bugs and analysis on this level.

I'll take it for now as I'm running the analysis.

See the dashboard for data that emerges: https://sql.telemetry.mozilla.org/dashboard/ui-resource-network-errors

The Bugbug bot thinks this bug should belong to the 'Core::Networking' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.