Originally reported in https://twitter.com/jitendravyas/status/908010217253756928 STR: 1. Open Developer Tools 2. Visit https://blog.nightly.mozilla.org/ or https://blog.mozilla.org/firefox/ Expected results: No error as before. The error is actually correct but annoying, so it should be suppressed. Actual results: An error saying "Style sheet could not be loaded."

The error occurs because source maps are enabled and because one of the original source is not available. If you disable source maps (the gear icon in the style editor has "Show original sources" - clear that checkbox), you'll see a "style.css" with 541 rules (there are two style.css, so you have to look at the right one). This says: /*# sourceMappingURL=style.css.map */ The source map URL is served ok: https://blog.nightly.mozilla.org/wp-content/themes/frontierline/style.css.map And, hmm, I can fetch the sass file ok too: https://blog.nightly.mozilla.org/wp-content/themes/frontierline/sass/style.scss Aha I looked in the browser toolbox's network monitor and this is bug 1330383. I think I may just fix that one in the interim since landing client-side source maps for the inspector is proving to be hard.

Mirror the status of bug 1330383.