URLs clicked in other programs won't load in Firefox
Just within the last 1-3 weeks (?) or so, I find that I can't click on links in other programs and have the URL load in Firefox, which is my default browser. They always used to load perfectly and switch me to the new tab in FF, but now they don't.
At first I tried disabling a couple of recent FF add-ons one at a time to see if one of them might have been the problem, but that didn't seem to solve it, though I may have missed one. Still, I can't imagine how an unrelated add-on could cause URLs not to load from other programs. I have tried loading URLs by clicking on them in Thunderbird, WordPad, MailWasher Pro, and even Libre Office, but all of them either just twitched the screen for an instant and then stopped, or else gave me a message such as "WordPad was unable to open the URL" or "There was a problem sending the command to the program" (Libre Office). However, when I copy and paste those same URLs into FF and hit Enter, those sites load perfectly.
I may be wrong in this, but it appears that something has changed within FF that now prevents links clicked in other programs from loading. My only other thought at the moment is that this may possibly have started about the time I upgraded from FF 10.0.2 to FF 11.0.1, but I have no firm evidence to support that theory.
This is really an annoying and inconvenient problem, so any help in resolving it will be hugely appreciated!