This is a common ritual for me, i like a page, i drag its url to a folder in the bookmarks sidebar. Today I realized i can't drag the URL at all to the bookmarks sidebar. I thought i research a bit, something from 2017 was mentioned that can't drag the bookmarks themselves in the sidebar, so I thought I try it myself and it failed. Couldn't drag the bookmarks as well. So please, need help. FF v: 62.0.2 / 64 bit. EDIT: next day, i come to the office, I left it running yesterday and suddenly everything works. Just in case if you were wondering, i did try yesterday to disable addons, tried safemode, nothing worked. However, today everything is fine. FF version is still 62.0.2 (64-bit) It wasn't a sticky key.