Playing videos breaks after reloading pages in ESR 78-based builds
We set browser.privatebrowsing.forceMediaMemoryCache to true in
#33856 (closed). It turns out that this caused a
regression which
lead to videos breaking if one re-loads pages (see comment
3 for steps to
reproduce).
Lucklily, this is already fixed in Firefox 80 and the patches are small. We should backport them.
To upload designs, you'll need to enable LFS and have admin enable hashed storage. More information