For a number of reasons I am not running the latest version of Firefox (45.0.1) and have stuck with 41.0.2, a major issue being that the extension "Adobe Acrobat — Create PDF 1.2" would be permanently disabled and there is no replacement available for the most recent versions of Firefox. There is much griping in various Internet venues about this issue. Mozilla has been of no value in this regard.

Anybody here know anything?

Adobe Acrobat Pro XI includes the Create PDF 2.0 plugin. Create PDF 1.2 was part of Acrobat Pro X, which is now obsolete and won't be getting any more updates.

Create PDF 2.0 is unsigned, which means that versions of Firefox that require code signing on plugins won't load it, but Adobe is planning to release an update that signs the plugin.

In the meantime, there are many PDF creator plugins in the Mozilla plugin center. Go to Menu > Add-Ons > Get Add-Ons and search for PDF.

Many thanks.

RE Point 1: I know. That's why I haven't updated from 41.0.2.

RE Point 2: That's been a problem for a while now, aggravating to everyone who's found out after the fact that Create PDF of whatever vintage has been permanently disabled by Mozilla.
Adobe claims that they're going to release a signed version, but they're sure taking their bloody time doing so.

RE Point 3: I've long since checked out what Mozilla's been offering in their Add-ons list and don't like them. I'll be waiting for the Adobe version.