I was using Thunderbird 91.0.1 64-bit under Windows 10 Home version 21H1. It uses the same profile as 78.13.0, which I had added a --allow-downgrade command line argument to its shortcut so that I could switch between 91 and 78 at will.

I auto-updated 91.0.1 to 91.0.2 . In the steps below I use the same messages each time. They're short plain text messages (notifications of a new reply to a MozillaZine forum thread)

1. I tried to print a single message using File -> Print, selecting the Nitro PDF Creator print queue. It prompted me for the file location and started the conversion but failed, reporting a conversion error. I've never seen that before. That's a print queue that uses Nitro Reader 5.

2. I tried printing a single message using "Save to PDF". That worked fine. Printing a single message to the "Brother HL-L2320D series" print queue which uses my monochrome laser printer also worked fine.

3. I tried printing a single message using "Microsoft Print to PDF". It printed a single page PDF with just Thunderbird at the top (centered) and the date/time stamp at the lower right corner.

4. If I select 2 messages using 91.0.2 and use "Save to PDF" it displays about:blank in the preview and prints the blank window (not the messages). It creates a single page PDF with just Thunderbird at the top (centered) and the date/time stamp at the lower right corner.

5. If I select 2 messages using 91.02 and use "Microsoft print to PDF" it creates a a single page PDF with just Thunderbird at the top (centered) and the date/time stamp at the lower right corner.
   I expected it to create 2 PDFs, even if they had the wrong content.

6. If I select 2 messages using 91.02 and and use the "BrotherHL-L2320D series" print queue it prints a single page with just Thunderbird at the top (centered) and the date/time stamp at the lower right corner. It should have at least printed one page per message.

7. If I select the same 2 messages using TB 78.13.0 and print using the "Microsoft Print to PDF" print queue it saves the first message as a .pdf file and then saves the second message as a separate pdf file. The PDF files look fine. That's what I expected it to do with 91.0.2 in 5).

The blank window in 3, 4, 5, and 6 is very similar to bug 1726779 . The main differences are I didn't see any mention of Bugzilla, I don't see it when printing a single message to a real printer (as opposed to a PDF file), and I only see that when trying to print more than one message at a time. This bug report is about problems trying to print multiple selected messages at the same time.

Probably we should just disable printing multiple messages at the time.

This doesn't fix the problem (it's still impossible to print multiple messages) but does prevent us getting into a number of failure states, including bug 1726779.

Depends on D123413

https://hg.mozilla.org/comm-central/rev/b2d0607e133f5a99424f51011cb5d8034a7ea55d

Marking current beta as affected as well.

Comment on attachment 9237614 [details]
Bug 1727107 - Enable message printing only when one selected message is displayed. r=mkmelin

[Approval Request Comment]
Regression caused by (bug #): bug 1711822
User impact if declined: user can attempt to print multiple messages or messages that aren't displayed, which doesn't work
Testing completed (on c-c, etc.): landed last week
Risk to taking this patch (and alternatives if risky): just disables some things, not risky

Comment on attachment 9237614 [details]
Bug 1727107 - Enable message printing only when one selected message is displayed. r=mkmelin

[Triage Comment]
Approved for beta

Thunderbird 91.0b5:
https://hg.mozilla.org/releases/comm-beta/rev/82f6c14e1da2

Comment on attachment 9237614 [details]
Bug 1727107 - Enable message printing only when one selected message is displayed. r=mkmelin

[Approval Request Comment]
Regression caused by (bug #): bug 1711822
User impact if declined: user can attempt to print multiple messages or messages that aren't displayed, which doesn't work
Testing completed (on c-c, etc.): in 92.0b5, not 91.0b5 as stated in comment 8
Risk to taking this patch (and alternatives if risky): just disables some things, not risky

Do we have a followup bug to potentially get multi-message print working? Or is it beyond the realm of possibility?

And where do we want to put "Printing of multiple messages is no longer supported" in release notes? If we put it in the Changed section, I'd think it is less likely to be noticed compared to being in Known Issues.

Geoff and me discussed it decided we won't implement that multi message printing. It could be doable but require quite some work.
I think it's reasonable that people have to open a message to print it. It's not like Firefox has print-all-these-urls, or print-these-bookmarks...

I guess under changed: Printing a message not shown is no longer supported (including multiple messages without viewing them)

Comment on attachment 9237614 [details]
Bug 1727107 - Enable message printing only when one selected message is displayed. r=mkmelin

[Triage Comment]
Approved for esr91

Rob, see comment 11 for relnote

https://hg.mozilla.org/releases/comm-esr91/rev/685167fd62f0

(In reply to Magnus Melin [:mkmelin] from comment #1)

Probably we should just disable printing multiple messages at the time.

But it worked in 78... This is a feature that at my company was used heavily... :( shaiza, and now 78 is not compatible with the 9x profile, so I can't even go back easily...

In terms of bug management, it's quite confusing when a bug is marked fixed whereas it has really been wontfixed (see comment 11), as the fix just disables the feature without providing the expected result mentioned in comment 0, point 7 - multiple selected messages should print as they used to in TB 78. Adjusting summary for the sake of clarity. I'm aware that Wayne has worked around the same problem by resolving duplicate Bug 1727865 wontfix and collecting duplicates there, which is good. We currently have 5 reports of this bug on record, and counting.

This is something that 5 heavy users in our office use every day. We will need to revert back to 78.14 and turn off auto updates.

How much extra work would be involved? Is this something we could donate toward fixing?

Please add back:( Everyone in our company used this functionally constantly.

Hello and thank you devs for all your work. We used this functionality on a daily basis. Please add us to the list requesting an underlying bugfix and multiple printing unlock.

We also depend on this functionality, please advise if it is likley to be addressed or if it has been permanantly wontfixed.

I filed bug 1737730 earlier, forgot to link it back to here.

(In reply to travis from comment #18)

Please add back:( Everyone in our company used this functionally constantly.

Yes! Pretty please! We used that feature all the time!

Won't fix? Oh No! After all these years, please don't tell me I am going to have to change email software to get this feature! I am a dyed in the wool thunderbird user, but this feature is one of the biggest reasons! Please tell me you will re-enable printing of multiple messages!

Try re-reading the title of this bug.

I have updated to the latest version just now, still cannot print multiple pages. Hit CTRL+P just like I have for years until today, nothing.

Unless your latest version is one of our daily developer builds, then that is correct. See bug 1737730 for the current status.

I cannot understand the decision to remove one of the most important features of the product to solve a bug that in all these years of use on a lot of computers had not affected me at all. In any case, the default batch printing is disabled, but not completely removed. The only option we have left is to use an old version (And also you have to download the emails again)...

Worthless now. The only reason I use this software is to print multiple pages. Deleted and won't be back.

(In reply to JuanCuesta from comment #28)

The only option we have left is to use an old version

You could install beta, where it works

(And also you have to download the emails again)

No, I don't think so

.

(In reply to lalamama22 from comment #29)

Worthless now. The only reason I use this software is to print multiple pages. Deleted and won't be back.

This was now fixed in 91.4.0, so it works in current versions.