There is no restriction for 64-bit. When TB is default email app, clicking a .eml file in File Explorer brings up TB, as desired. I suggest you recheck that TB is the default, both in TB and also in Windows. In Windows 10, you can search for 'default apps' and then confirm TB's status.

TB is the default app on its settings page, and it's the default email app in W10. If I left click on a .eml file, yes, TB opens. My issue is right-clicking on a file (of any type) in File Explorer, selecting Send to...Mail Recipient.

This appears to be a W10 issue, as a quick web search indicated it is fairly common with W10. Is mail recipient an option when you click 'send to'?

I had responded with a possible registry entry, but that apparently didn't get by the forum moderator. That may be a possibility to research.

Yes, it's an option but clicking says it's not available. I wonder if I'm not reading the error message right. I did see a post that the wording is slightly misleading. Screenshot attached.

locate 'default apps' in windows. Search for Mail entry. That should show Thunderbird. It should also show entry for MAILTO. Select Thunderbird. That should fix it.

I have an idea. More tomorrow.

I have a related problem. I'd like to write it in a separate thread, but even though I'm logged in to this forum, I cannot find where I can open a separate problem, only finding the database search field, which turns up nothing but this thread.

My problem is this: I got an automatic update to v 91.5.0 yesterday (15 Jan) on my Dell laptop that runs Win10 Pro. T-Bird ran fine yesterday after the update. When I went to bed I shut it down, along with all other applications I was using; my laptop slept the night, as is usual; I don't power it down for the night.

Today, I cannot open T-Bird; I get a message saying it's already open, and Task Manager says there are two instantiations. I close them via TM and retry with the same result. The new profile from the update is labeled <characters>.default-release. I got the same T-Bird update on my PC (also running Win10Pro), and that instantiation runs fine, so far; it's profile does not have the -release suffix.

I tried both renaming the -release profile and emptying it so I could replace it, but I could not, completely: there are a few .msf files and the parentlock file that I cannot remove or delete; I get an error message saying they're already open in Thunderbird, even though T-Bird now is not installed at all.

Cold booting my laptop did not solve the problem. Uninstalling and reinstalling T-Bird (the current download is still 91.5.0) changed nothing. Uninstalling T-Bird, then cold booting, then reinstalling T-Bird changed nothing.

Thank you for your help.

Eric Hines

First, stepping into another thread can confuse volunteer helpers. I do understand that it's a bit confusing, locating where to ask for help. I will give a quick assessment, but if it doesn't work, please open a new request at https://support.mozilla.org/en-US/pro.../install-migrate-and-update

Okay, assuming you have TB installed, it sounds like TB is not connecting to profile. If that is correct, add -p to desktop shortcut (on the target line, a space or two to right of '...thunderbird.exe' The restart TB and you should be prompted with a menu to select the right profile. Click 'create profile' and locate the proper folder. That may do it. Again, if the problem is bigger, please open a separate request. Thanks for your understanding.

David,

I'd like to, but when I'm on https://support.mozilla.org/en-US/products/thunderbird/install-migrate-and-update , I cannot find anywhere to actually ask a question. Under the Get Help menu item, Ask A Question just takes me to a database search with no field, space, link for actually asking a question. I do the search and the search just takes me to the same database search with no field, space, link for actually asking a question.

I can find no place to ask, only to search databases.

As to your suggested solution, alas, Thunderbird will not open at all; I just get the error message "Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window. |CLOSE CANCEL|"

Thanks

Eric Hines

David,

On second try, your solution regarding -p worked. I selected Create Profile, per your suggestion, deleted everything from that new profile and copied the contents of a known good profile (a recent backup) into it.

T-Bird runs properly, now.

Thank you, and I owe you a beer if you're ever in Plano, TX.

Eric Hines

I've looked at Control Panel - Programs & Features. I now have both x64 91.5 and x86 91.4.1 installed. No wonder W10 is as confused as me. The apps list on the Windows Key takes me to 91.5. The Set Default Apps just shows me a button so it could be either. I'll back up my profiles, uninstall both and do a clean install of 91.5. I don't have time to do that right now so don't expect anything more from me for a week or two.

But this is all caused by 91.4 not updating automatically and a fresh install of 91.5 not replacing 91.4. That's the bug for Mozilla to address. I could almost understand it if it were a major upgrade, but 91.4 to 91.5 is incremental - but why x86 to x64?

You may have had both because initial setup you did was probably x86, and TB, when updating, updates the existing setup. However, if you downloaded an update, it would have been x64 and that is where the problem may have begun. I'm glad you found the root issue and hope all goes well when you reinstall.

David,

What's interesting to me is that the same update to T-Bird (which, in all cases, originally was back in the X86 days) works just fine on my wife's laptop (same Dell model as mine, but a couple years newer) and on my Dell PC (an older model, but not that old).

My wife did have a serious upgrade problem with Firefox's latest update.

In both cases, the problem involved profiles labeled <xxx>.default-release instead of <xxx>.default .

I have to wonder if that labeling had an impact. But doesn't explain why T-Bird ran fine after the upgrade on the day of the upgrade, but after being closed for the night, I ran into the Won't Open problem the next day.

Eric Hines