The preference that should be reset is print_printer. Right-click, Reset. Did you recently install a new printer or make another printer the system default? When you select File/Print..., is it not possible to select a printer?

Thanks for getting back. No new printer, same default printer. Can print in Firefox and Adobe Acrobat. Both recognise the printer. There is no print.printer reference in config editor at all. Thunderbird was fine, now it isn't. When selecting File/Print, the printer is selcted by default, click print and Thunderbird starts searching, the little disk keeps spinning and I have to reboot to get out of Thunderbird. But , your reply kicked in the idea of just adding the printer again in the dialogue box. I'll let you know how that goes. thanks.

No luck with re-adding the printer.

The relevant preference is print_printer, not print.printer.

as I have tried to explain, print.printer or print_printer is not in Thunderbirds config editor. When I type either of those into the config editor both of them produce a blank page There are a lot of print. somethings and a couple with the underscore but none ending in .printer or _printer.

In my Config Editor I typed: print The image below shows the results.

You can see the 'print_printer' line and the name of the printer. Below you can see various 'print.printer_printer name...' lines.

If you can see all the 'print.printer_printer name...' lines then try creating the 'print_printer' line.

Right click somewhere in the 'about:config' and select 'New' > 'String' type: print_printer click on OK then add the Value which is the name of your printer as shown in all the 'print.printer_printer name...' lines, but without any of the underscores. click on OK. See my image as an example.

Another check if above cannot be done or does not work: In your Profile name folder there will be a 'prefs.js' file. You can open a 'prefs,js' file using a text editor like Notepad to see if it has the print_printer line. Do you have more than one 'prefs.js' file perhaps with a number of same size? If yes does that one have a 'print_printer' line ? If yes: Exit Thunderbird Put the 'prefs.js' file on desktop temporarilly. Rename the 'prefs-1.js' file to say 'prefs.js' Start Thunderbird.

If only one 'prefs,js' file: Exit Thunderbird. Make a copy of the 'prefs.js' file and save as a temp backup on desktop. Edit the 'prefs.js' file removing all lines that start with print. Save the file Start Thunderbird. select email and try to print, but this time select the printer.

Very comprehensive, thanks for takeing the time. Will need time to follow your instructions. Understand the config editor bit, but not so confident with prefs.js file advice. I will get back as soon as I have a result of some kind. The screen shot is very useful. Thanks again.

Well, eventually got as far as finding my prefs.js file. Only one, so saved it to my desk top.

The file has mixed information regarding my printer. 3 variations in fact. But for the moment I want to follow your last bit of advice, which was to delete all references to printer_printer. save the file and exit.

Before I do that, may I ask you another question? With prefs.js opened in text/editor: When I start selecting the printer references, red lines start apearing under almost all the lines in the file and I am loath to delete anything until I know what is going on. Is this what text editor does anyway and should I just go ahead and delete the selected files ?

I would only edit the prefs.js file as a last resort, as it could result in more problems than the original. It is very odd that you don't have the correct printer preferences. Did you install TB before there was a printer connected to the computer? Is there a printer defined as the system default? If so, it might be worth running the full TB installer over your existing setup (doesn't affect the profile folder) and see if it picks up the system default printer. Even removing the printer from OS X settings and adding it again might work, as sometimes an OS update removes default device associations - at least, it does in Windows.

sfHowes and Toad-Hall, thank you very much for your help. I've followed it right down to reloading TB, deleteing and reinstalling my printer, plus the advice regarding config editor and prefs.js file but the problem still remains. If I was running windows I would by now have guessed that I had a virus, but I'm not.

I plan to try one more thing. The prefs.js file in Firefox has my printer listed. I can print out of Firefox, Adobe Acrobat and LibreOffice so, I'm going to try and select/copy all the info for my printer( very carefully!), open my prefs.js file in TB and try and work out how to paste that info into TBs' prefs.js, closeing TB before I save it. Erm, that's the theory anyway.

I have learned a lot through our discussions, I consider it time well spent, very grateful.