Version 42.0 can only be updated to vesion 43.0.1
I've got a PC on which Firefox 42.0 is installed.
I would like to update the 42.0 vesion on that PC. After clicking on the "Check for update" button in the "About Firefox" menu, I got a message that it can be updated to version 43.0.1.
Why not newer versions?
I couldn't use version 40.2 to post this question because when I clicked on the "None of these solves my problem" button, version 40.2 crashed. So I used version 49.0 on the same PC instead.
Version 42.0 also crashes when I click on "Troubleshooting information" under the Hep menu.
43.0.1 was served to Windows users using older versions at the time due to Windows XP and Vista users in mind. WinXP/Vista users were also served 43.0.1 on mozilla.org at the time to then update from. Firefox Release setups from versions 43.0.2 to 48.0.2 were signed in a way that WinXP SP1 and users not updating Vista enough could not run them. Then there was the 47.0.2 which was a transition Release for those who were using 47.0.1 or older to check for a couple things on Windows.
Since you would get full and not partial updates anyways you could download the full setup for Windows from www.mozilla.org/firerfox/all
Oh, I see. Something like a qualification check before promotion.