So I was having a problem with some stuff on SO not working that was similar to this post on Meta which recommended clearing the browser cache.
Now it wasn't working in both Chrome and Firefox and I had never logged in to SO on FF before today so FF couldn't have cached the file itself. Tried hitting refresh multiple times and even tried Ctrl-F5 with no luck.
I cleared the browser cache in Chrome only, and after that it started working on both Chrome and FF. How could clearing the cache of one browser affect the other?