"About Firefox" not available in Firefox 39 & 40 on Mac
On Windows and Linux, the "About Firefox" screen can be accessed via the "hamburger" icon in the top right of the browser.
On Macs, the "About Firefox" screen can only be accessed via the Firefox menu, in the Mac menu bar, next to the Apple menu.
In Firefox 38 (for Mac), the "About Firefox" option showed in the Firefox menu. In Firefox 39 & 40, there is only an option to quit.
Alla svar (4)
Did you check other menus like the Help menu where About can be found on other platforms?
Just to be sure:
Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.
- Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
- Do NOT click the Reset button on the Safe Mode start window
Neither the Help menu nor the newer hamburger menu have had an entry for "About Firefox" on the Mac. It's only ever been accessible via the Firefox menu.
I've filed a bug report for this issue here: https://bugzilla.mozilla.org/show_bug.cgi?id=1195049
My current workaround is to open a new tab and enter "about:" in the address bar. This lets me see the current version number, but doesn't let me check for updates, which is what I was looking for in the first place.
I relaunched Firefox in safe mode, and I observed the same behavior.
I'm using the default Firefox theme.