Category Archives: firefox

Firefox hangs after Mac OS update

I recently updated my 2010 MacBook Pro all the way from Snow Leopard 10.6.8 to Mavericks 10.9.1.

Today, I updated Mavericks to 10.9.2 in order to fix the nasty Mac OS X SSL vulnerability.  Sadly, after the update, when I tried to start Firefox, it would hang.  I tried repeatedly, but I would get no window, no error, just a Firefox main menu with no File, Edit or other menus.

I did a lot of research but could find nothing that explained precisely this behavior.

I tried installing a second copy of Firefox.  I tried deleting my original installation.  I tried turning off my firewall.  I tried deleting my profiles.  I went through all kinds of machinations, but nothing worked.  No matter how clean a start I seemed to give it, Firefox would (a) hang, and (b) fail to quit.  I had to Force Quit every time.

Well, here’s the “funny” part of the story.  After all that, I somehow ended up swiping to a second desktop on my Mac (by scrolling to the right with three fingers).  And what was there?  Firefox.

Coming from Snow Leopard, I’m a little fuzzy on exactly why, how, and when Desktops come into being and how apps get allocated to them.  But, for whatever reason, Firefox acted for all the world as if it was hung, while it was actually just running on a different Desktop.

Damn.

What to do when Firefox eats all your CPU

I tend to have a lot of tabs open in Firefox at any given time.  It’s not unusual for me to have 20 or 30 open, and I’ve been known to hit 40 or 50 at times.  (I wouldn’t survive without the sessionsaver extension.)

This can sometimes get Firefox pretty upset.  Windows Task Manager shows nearly 1GB of Mem Usage.  And sometimes CPU just hovers at or near 100%.

Sometimes Firefox becomes nearly unresponsive.  This is a sure indication that it’s time to shut down and reboot, but it can take a long time just to get focus under these conditions.  One thing I’ve found that works is, ironically, to lower the priority of the firefox.exe process in Task Manager.  If you set it to BelowNormal, it will usually help Firefox to backburner what it’s doing (must be garbage collection or memory consolidation) and come back to processing UI events.   But it really is a good idea to at least shut down Firefox, if not the whole machine, when you get to this point.

One not-so-funny thing about having a bunch of tabs saved in a session:  I once opened Firefox while at some public place with broadband, maybe a coffeehouse or hotel, I don’t remember.  I had thirty or forty tabs saved in my session, and when the blast of requests came from my machine all at once, the wireless router decided I was up to no good and blocked me from further Internet access.  I’m surprised it only happened that one time.