In iCloud, I have tried to use Firefox in the bookmarks set up options area. I have installed the Firefox add-on iCloud Bookmarks on Firefox. When I try to apply Firefox to iCloud, a window opens to tell me i require the add-on iCloud Bookmarks to be downloaded and added to Firefox. (It is already installed as an add-on in Firefox.) There is a spinning circle beside the Apply button. Why is this add-on not working? (I am using the most updated version of Firefox right now.) Thanks for your anticipated help with this problem.