hello, other users with this problem all had an embedded intel hd3000 graphics card with an old driver present. in case this also applies to you, here would be a link to update the driver, which in turn should also address the black firefox problem: https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=23764 (for win7 64 bit) https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=22642 (for win xp 32bit)

in case this doesn't solve the issue or does not apply to your system, start firefox into safemode by pressing the shift key while the application is launching & disable hardware acceleration in the firefox menu ≡ > options > advanced > general (that setting will take a restart of the browser to take effect).

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Переустановка Firefox после появления черного экрана проблему не решила. После Вашего совета запустить Firefox в безопасном режиме не удавалось нажатиями Shift при его запуске. Запустил восстановление системы на 09.10 2014. После этого Firefox перестал запускаться с ошибкой. Переустановил Firefox еще раз. После этого Firefox запустился в безопасном режиме. Далее по Вашему совету снял птичку с "по возможности использовать аппаратное ускорение". Все работает. Импортировал из резерва закладки. Спасибо!

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Reinstalling Firefox did not solve the black screen problem. Following your advice to run Firefox in safe mode, I tried to do this by pressing the Shift key when I start it. But without success. Further, I launched the System Restore on 09.10 2014. Thereafter Firefox started and stopped with an error. Then I reinstalled Firefox again. After that Firefox starts in his safe mode. Next, to your advice, I took the bird from "as much as possible to use hardware acceleration". Everything works. I imported from the reserve bookmarks. Thank you!