This addon causes high CPU usage on some webpages. I would guess it conflicts with javascript on those pages. I had only installed this addon and never used.

I hate it because it keeps messing up the size of Firefox. I always put it in full screen, but when I open it in the morning it takes the shape of this Kantu application. Also, It does not work on the first screen opened. I have to open a second tab for the macros to work. What a pain!