If you have submitted crash reports then please post the IDs of one or more recent crash reports that start with "bp-":

• bp-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

You can find the report ID of recent crash reports on the "Help > Troubleshooting Information" page (about:support).

• click the "All Crash Reports" button on this page to open the about:crashes page and see all crash reports.

Alternatively you can open about:crashes via the location/address bar.

See also:

• http://kb.mozillazine.org/Mozilla_Crash_Reporter
• https://support.mozilla.org/kb/Mozilla+Crash+Reporter

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox title bar.

• "3-bar" menu button > Exit (Power button)
• Windows: File > Exit
• Mac: Firefox > Quit Firefox
• Linux: File > Quit

In case you use "Clear history when Firefox closes" then try to disable this feature.

• Tools > Options > Privacy > Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" > Settings
• https://support.mozilla.org/kb/remove-recent-browsing-search-and-download-history

Separate Issue; Your System Details shows;

Installed Plug-ins

Skype Web Plugin 7.2.0.422 Skype Web Plugin
Having more than one version of a program may cause issues. You must remove the older programs. Then get the current full installer.