51 has been out a few days now .
Problem i had was with 64 bit Flash crashing on me .
Here is what i did .
Whenever I go to any site which uses Adobe Flash, Flash will crash immediately.
Firefox itself will still work but any feature supported by Flash on that given page will NOT.
I even uninstalled Firefox completely, installed pristine, fresh copy and same crashes happen.
Finally today I was able to find solution.
Apparently it's all about Adobe Flash protected mode, which seems to be incompatible with 64-bit systems.
IMPORTANT! Disabling "protected mode" through Firefox doesn't work.
You can go Tools\Add-ons\Plugins\Shockwave Flash\Options, disable "protected mode" there, restart Firefox and it doesn't help.
What works is this...
Open File Manager (Windows Explorer), navigate to:
C:\Windows\SysWOW64\Macromed\Flash
You'll see
mms.cfg file there.
Open it with any text editor like Notepad.
It looks like this:
SilentAutoUpdateEnable=0
AutoUpdateDisable=0
AnalyticsUserChoice=0
AnalyticsThrottleValue=0
DisableAnalytics=0
Add the following line:
ProtectedMode = 0
It's case sensitive, so make sure it looks exactly like It was Written.
Save the file, restart Firefox and you should be good to go. No more Flash crashes.
Note. Windows may not let you save the above file.
In that case "take ownership" of
mms.cfg file (
http://www.howtogeek.com/howto/wind...ership-to-explorer-right-click-menu-in-vista/)
Recheck the above file after next Adobe Flash update because it may delete added line.