I love the Firefox Add on DownThemAll. I’ve been using it for years. I have version 2.0.19 of DownThemAll on Windows 10 (FF v 48) and all of a sudden started getting File Access Errors anytime I tried to download anything. I tried many different suggestions I found on the internet but nothing worked (changing filenames, changing directory paths, etc.). I guess I have been lucky to not have experienced this error before as I see many posts on this topic out there.
This morning I tried something different. I created a shortcut for Firefox on my desktop – just dragged the Firefox shortcut from my start menu to the desktop and then I right clicked on the shortcut and selected ‘Run as Administrator’. DownThemAll works again. I know this is not the optimal thing to do but I am in a pinch as I need to download some large Linux iso files so now I’m happy once again.
To run as administrator all the time, view the shortcut properties, select Advanced and select Run as Administrator and click ok (or apply) to save that so Firefox always will run as administrator.
Hope this helps someone out there.