Thunderbird doesn't start/open anymore. (Windows 10)

What action do you see.

To diagnose problems with Thunderbird, try one of the following:

• Restart Thunderbird with add-ons disabled (Thunderbird Safe Mode). On the Help menu, click on "Restart with Add-ons Disabled". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender.
• Restart the operating system in safe mode with Networking. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, OSX

If safe mode for the operating system fixes the issue, there's other software in your computer that's causing problems. Possibilities include but not limited to: AV scanning, virus/malware, background downloads such as program updates.

Thank you Matt for your input! Unfortunately, I've tried all those steps and nothing works. I disabled (temporarily) the antivirus I have (Norton), I tried the Safe Mode, uninstalling and re-installing Thunderbird and nothing works. When I click on the Thunderbird Icon, it tries to open but it cannot. All I can tell you is that the program was working fine for a long time, but after the last update (Thunderbird update) it never worked again... I have Windows 10. I even tried to run the program in an older version (the one that was working) but it didn't allow me to do that... I am at my wits end. And I liked the program! Much better than Windows Mail, which I have no choice but continue to use because Thunderbird doesn't work anymore... What else can be done? Please help! Thanks!

I would say the problem falls squarely on Norton's Firewall component. So check it is set to allow Thunderbird to execute. If you have at some point accidentally blocked Thunderbird in one of the many pointless Norton's windows it will stay that way until you either fix it in Norton's or uninstall it. My preferred suggestion for anyone using Norton's is uninstall it. Using the uninstaller Symantec have on line. Install it again letter if you so desire, but personally I don't think the product is anything more than scareware. (I swore by it 20 years ago when Peter Norton owned the company. Like McAfee, as soon as the guy that invented it sold it it turned to rubbish)

Hi Matt and thank you again for trying to solve this problem I'm having with Thunderbird. Unfortunately, I know it's not Norton because I only installed Norton Antivirus a couple of weeks ago and Thunderbird was already giving me trouble before that. It's been a couple of months, or more, I don't remember, but I am positive that it has to do with the last update to Thunderbird. Before that, it was working fine. I really miss Thunderbird! It's a good program, when it works... I don't know if anyone else is having the same issue, but I don't think I'm the only one...

re : I tried the Safe Mode, But you did not state what test mode you are talking about. There is Thunderbird Safe Mode and there is computer Safe mode with Networking.

• Start the computer in 'Safe Mode with Networking'
• then start Thunderbird.

What happens ?

If Thunderbird will not run then it maybe being blocked and the usual culprit is a Firewall. It is possible that the Firewall does not see the new updated Thunderbird is the same as the older version. Hence suddenly it does not work.

If you have Norton then it is likely you are using the Norton Firewall.

Exit Thunderbird - check it is not running in the background - check with Task Manager.

First make sure you do not have two Firewalls trying to run as they will cause all kinds of conflicting issues. Norton should be the only one being used.

Then access Norton Firewall and you should see Thunderbird in the list as programs that are allowed.

If Thunderbird is not in the list then add it as an allowed program.

If Thunderbird is in the list then select Thunderbird and block it then ok it. Then access again and reset Thunderbird to be allowed and ok it. This could kickstart it again.

Now try to start Thunderbird. What happens?

re: When starting Thunderbird from shortcut icon: Right click on Thunderbird icon and select 'Properties' General' tab 'Attributes': REad-Only and 'hidden' should not be selected.

'Short cut' tab Check target is correct If using 32bit: Target: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" If using 64bit: Target: "C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe"

Click on 'Security' tab Do you have correct permissions ?

click on OK

Try this: Right click on Thunderbird icon and select 'Run as Administrator' Did thunderbird start this time?

@valley10,

What happens in your safe mode and other testing?

Thank you Matt and Wayne. I've tried absolutely everything you both suggested and nothing works. When I click on the Thunderbird icon, either normally or as an administrator, the program tries to open, a small window flickers on the upper left corner of the screen and nothing else happens. It cannot open. I can open the write mail pane, but it won't send emails... I even uninstalled the previous antivirus I had (Adaware) to see if that would solve the problem... it didn't. It has to be a problem with the update. I've installed and uninstalled Thunderbird so many times, that I can't count them anymore. I think that I'll have to continue to use the Microsoft program that I really don't like at all... Thanks for trying to help me... Valerie

In Windows' file explorer, go to C:\Program Files (x86)\ and delete the Thunderbird program folder. Then download and install from http://getthunderbird.com/

If that version still has the same problem, try the version at https://releases.mozilla.org/pub/thunderbird/releases/60.3.3/win32/en-US/Thunderbird%20Setup%2060.3.3.exe

Please tell us your results

Thanks again, Dwayne, but these two options didn't work either. The program downloads and puts an icon on the desktop, as normal. When I click on the icon, it tries to open but it only shows a little window on the upper left corner, that flickers for a little bit and then disappears. It's always the same problem, no matter what I try. At this point, I'd say, let's leave it alone. I'm using Windows Live Mail for the time being and it's working fine. Thank you and your colleagues for trying to help me. I have installed and uninstalled Thunderbird so many times, that I lost count.... Best regards, Val