In the address bar, type about:crashes<enter>. Note: If any reports do not have BP- in front of the numbers/letters, click it to submit them.

The crash report is several pages of data. We need the report numbers to see the whole report.

Using your mouse, mark the most recent 7 - 10 Submitted crash reports, and copy them. Now go to the reply box and paste them in.

Please, Do not post a screenshot ! !

For more help on crash reports, see; https://support.mozilla.org/en-US/kb/firefox-crashes-asking-support

I see issues reported at mozillaZine in the current Nightly thread with Nightly on Mac.

• http://forums.mozillazine.org/viewtopic.php?f=23&t=3070345

Could be this bug:

• Bug 1689807 - macOS startup crash "Code Signature Invalid"

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)