Starting just in the last week (I think since the update to 42), I am unable to use the mouse to move tabs. The Ctrl+Shft+PageUp/Down still moves the tabs, but click and holding on them with the mouse will not let me move them. On top of that, I can not rearrange icons in customize, and when using a bookmark sidebar, I am unable to arrange the bookmarks. I tried disabling all extensions, themes, and even tried creating and using a new Firefox profile. I still had the problem with a vanilla profile. I can drag and drop in Windows as normal, just not in Firefox. Along with this, in Thunderbird, starting at the same time, I am unable to drag and drop emails between folders. All other browsers work just fine. I even tried turning off Malwarebytes and Norton, but it still doesn't work. Using fully updated Windows 10 64bit. Could use any help or suggestions.