Create a new profile as a test to check if your current profile is causing the problems.

See "Basic Troubleshooting: Make a new profile":

• https://support.mozilla.com/kb/Basic+Troubleshooting#w_8-make-a-new-profile

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.

If that new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

See:

• http://kb.mozillazine.org/Firefox_crashes
• https://support.mozilla.com/kb/Firefox+crashes

Here is the crash report (for the record)

https://crash-stats.mozilla.com/report/index/c545b608-405a-4f15-953b-9a1932111110

... and related bug:

658780  NEW Start-up crash with incompatible version of some extensions <snip>

Crashes involving incompatible Firefox extensions can also be resolved by restarting in Firefox Diagnose Firefox issues using Troubleshoot Mode and and Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems (some people may find that easier than creating a new profile and transferring profile data and settings).