We have broken Yandex.Music playback
HTTPS Everywhere breaks streaming of Yandex.Music, tested with current stable (as of date of writing) version of plugin under Ubuntu GNU/Linux, Firefox 28.
Yandex.Music is not fully routed through HTTPS anyways, so I don't really understand why this particular rule is there in the first place.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information