I’ve examined a couple of dozen links on how to fix ‘‘Mozilla Firefox (Not Responding)’’ ? Most are for old versions. I think all I have found so far are pre-2013. I’m having the problem with v47.0.
Reviving because I’m having the same problem-My Firefox won’t open. I’ve got Windows 10, which recently(and constantly) updates, and I’ve tried both reinstalling Firefox and rolling back my Windows to an earlier date, but nothing works.
I am still seeing it a lot with W10 and FF48.0.2. I mostly read so I like FF because of the several little features in the search add-ons and read formatting features. So I put up with it. But, Czarcasm, I can see problems for others.
The only solution I know is to Refresh Firefox. This will reset everything but your history and passwords and bookmarks and such. You’ll have to reinstall all your extensions, and tweak any settings you might have lost.
I eventually did this after Firefox was lagging so badly that I couldn’t stand it anymore. It made a huge difference.
Will that help with Plugin container crashes? My plugin cointainer crashes at least once a day, and I’ve made all the configuration changes for FF to address that I can find on the web.
It’s not lagging-it’s not opening at all. I have no access to passwords, extensions, bookmarks, and of course I cannot refresh what doesn’t exist. As already stated, I have uninstalled and reinstalled the program, to no avail.
The most I can get is an image of the start page when I mouse over Firefox image on the toolbar after I attempt to start it up…but that is it.
Update: Despite several updates from Firefox in the last couple of days, the situation still hasn’t changed. I still get nothing but the tiny preview window from the startup bar when I try to open it.
Sometimes when I have trouble with Firefox not starting, I’ll look in Task Manager and see that there is more than one instance of Firefox.exe running. If I kill them all then restart Firefox that fixes the problem.
Once again: I have uninstalled Firefox completely, then reinstalled it, and it still doesn’t work.
these days Chrome seems to work much better than Firefox so try that if you haven’t.
That’s what I’m using in the meantime…but I would still like an actual solution to my problem. I can’t even import my bookmarks from Firefox.
Try to disable flash. It makes a huge difference. You can still very easily watch flash videos if you choose to: just click on the image and click “allow.”
Instructions here.
Sometimes there isn’t enough bad booze in the world, I swear.
From your post:
I’m kind of tired of pointing out the obvious problem with this “solution”.
I give up. I guess I’m just not brilliant like you are. Please explain what the “obvious problem” is for those of us who are not as smart as you are.
What icon?
What bar?
What Firefox?
Thank ghod for Laird’s Applejack, to get me through threads like this.
This is weird.
From a firefox help page:
“If Firefox previously worked but suddenly doesn’t start, it may be due to some corrupt data in your settings. Uninstalling and reinstalling Firefox would not fix this problem because your settings are not removed on uninstall.”
Huh. That seems counterintuitive.
Believe it or not, that same page you linked to gave me the answer to my problem. 
It turned out I had a corrupted profile(which doesn’t get deleted and/or replaced when Firefox is deleted and then reinstalled), and it told me how to delete the profile completely. I am now posting this from Firefox, and all is apparently well.