Hi getfitguard-couponmom, how does the printing work on those sites in other browsers? For example, the button:

• opens a popup window with a simplified layout and then fires the print dialog?
• generates a PDF for download (or to open in a new tab)?
• prints a frame without a new window or PDF?

If the part of the page that won't print is in a frame, you could try this:

• right-click (on a one-button mouse, Ctrl+click) the background in that area
• expand the This Frame submenu (if this is not available, it's not in a frame)
• click Print Frame...

Could you test in Firefox's Safe Mode? In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, any userChrome.css/userContent.css files, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the option/alt key when starting Firefox. (On Windows, hold down the Shift key instead of the option/alt key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

On other browsers (Google Chrome, Safari) selecting the print link embedded on a web page either opens up the print feature built-into the browser (Chrome) or Apple's print system (Safari). Previously, Firefox would immediately bring up Apple's print system and then I can choose to save as PDF file. Now, nothing happens and comes up with the error. The only workaround is File>Print from the web browser. But as I mentioned that doesn't always work.

Are any of these sites available to test without an account/login?

I gather there was no "This Frame" available on the context menu?

And there was no difference testing in Firefox's Safe Mode?

I am on Windows 7 and I think I have a similar issue that I just discovered this morning. 78.0.2 was installed on July 9, 2020 6:31 PM.

Haven't taken the time to look into the "source" of my problem, although it may be with the Print Edit WE extension; the Print button in the Preview (inside Firefox itself) doesn't show the "native Windows dialog box" that allows me to select how many pages will be printed (along with other Windows controlled features related to Printer software control). Just goes directly to Printing all the pages that are showing in the Print Preview window. and lost the ability to use features that are in Windows for my printer.

Happened for me @gmail.com (a SSL connection, too) as I was printing a few emails that I received yesterday. Thru me for a loop, as it didn't happen a week ago on Mon the 6th with other "weekend" emails I had received and wanted to get "down on paper".

This support thread was started & posted from Firefox on Mac OS X 10.12, so your issue may not be related to what I just explained - but close enough for consideration that 'something' was changed in 78.0.2 that affected at least me, if not both of us.

Hi the-edmeister, if Print... bypasses the Print dialog and just immediately shows the progress bar, could you make sure you don't have print.always_print_silent set to true in about:config?

Hi jscher2000, I have not tried safe mode yet. I did discover that turning off tracking protection will allow the normal print dialog box to appear without any errors. However, it can still take over a minute to appear. When tracking protection is turned back on, the printing error message shows up.

Hi the-edmeister, if Print... bypasses the Print dialog and just immediately shows the progress bar, could you make sure you don't have print.always_print_silent set to true in about:config?

Yes that is what happens. print.always_print_silent is false and prefs.js also shows it as false.
Not using any of the 'triad of "user" files' in this Profile, so no user.js to lock any prefs. Although if I was to include that pref in user.js it would be false, too. Too damn many faults in print code to not preview before printing thru Firefox.

I still haven't taken the time to check my other 78.0.2 Profiles to see if they might be affected, too.

jscher2000 said

Hi the-edmeister, if Print... bypasses the Print dialog and just immediately shows the progress bar, could you make sure you don't have print.always_print_silent set to true in about:config?

Yes that is what happens. print.always_print_silent is false and prefs.js also shows it as false.
Not using any of the 'triad of "user" files' in this Profile, so no user.js to lock any prefs. Although if I was to include that pref in user.js it would be false, too. Too damn many faults in print code to not preview before printing thru Firefox.

I still haven't taken the time to check my other 78.0.2 Profiles to see if they might be affected, too.

That problem is gone for me in this Profile now. And no issue with that 2nd Profile, either.

Strange that restarting Firefox and even logging out of my Win7 LUA didn't fix it when I tried the other.

Ed