none of the previous solutions mentioned this version. also many people complained about the fix being only temporary.
Maybe you can provide more information,
Have you tried using Firefox's safe mode does that prevent the messages appearing ?
(Not intended as a fix, just a first troubleshooting step)
a miracle has happened ! the only thing i did was add Adblock Plus from mozilla and i havent had any problems since (or ads on facebook).
the message is on the top bar, the whole thing stalls out for about 30 seconds but then comes back on. screen goes grey and nothing can be done but wait.
Maybe you have some form of malware/adware or some odd toolbar inadvertently installed. It looks like Adblock plus has solved the problem for now.
In addition to a sceenshot of the problem looking at the error console may give some clue as to what is happening. (If you can reliably reproduce the problem after first clearing all the error messages)
This problem is a chronic disease in firefox, and I've tried all the ways, but I could not find a solution.
Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.