Product Firefox Release Channel release Version 56.0.2 Build ID 20171024165158 OS Windows 8.1 OS Version 6.3.9600 bp-43029bc2-1d54-46df-b478-82b701171106 '''Signature:''' shutdownhang | mozilla::SpinEventLoopUntil<T> | mozilla::net::nsHttpConnectionMgr::Shutdown MOZ_CRASH Reason MOZ_CRASH(Shutdown too long, probably frozen, causing a crash.) eps2003csp11.dll = Company: EnterSafe sysfer.dll = Symantec CMC Firewall IPSEng64.dll = Symantec Intrusion Detection -------------------------- Check all of your programs for updates. This type of crash is sometimes caused when the browser takes too long to close. [https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode Start Firefox in Safe Mode] {web link} by holding down the '''<Shift> ''(Mac=Options)''''' key, and then starting Firefox. A small dialog should appear. Click '''Start In Safe Mode''' (not Refresh). Do this several times. Is the problem still there? https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding