Rated 5 out of 5 stars

FF 46.0.1 x64
Update: this bug is fixed in 0.4.7

This review is for a previous version of the add-on (0.4.6). 

Could you check to see if this also works for you as well, before I upload it.
https://choggi.org/misc/CuteButtonsCrystalSVG/CuteButtonsCrystalSVG-0.4.7.xpi