Hi,

I am surprised by your message, but I found a solution that has been tested and approved that I share with you so that you can do it easily

https://support.mozilla.org/en-US/questions/1209242

best regard

So sorry but in the body I referred to Thunderbird but mistakenly posted it on Mozilla support, tried to post it 1st time on Thunderbird forum but it didn't take and then posted it in error here. It's Thunderbird that keeps giving the error message. Do you want me to re post it in that forum or direct me to an answer for T Bird?

You do not need to repost - you have posted in the correct place.

The link which was posted is for Firefox, we just need to modify it for Thunderbird. I will attempt to do so below

Let’s do a full clean re-install;

Download Thunderbird For All languages And Systems {web link}

Save the file. Then Close Thunderbird.

Using your OS' file browser, open the Programs Folder on your computer.

• Windows: C:\Program Files (x86)
• Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac
• Linux: Check your user manual. If you installed Thunderbird with the distro-based package manager, you should use the same way to uninstall it.

If you downloaded and installed the binary package from the Thunderbird download page, simply remove the folder Thunderbird in your home directory.

++++++++++++++++++++++++++++ Look for, and remove the Mozilla Thunderbird folder.

(If you see a profiles folder, Do Not remove it or anything below it.)

After rebooting the computer, run a registry cleaning scanner if you have one.

Then run the installer. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

Thanks. Last time I reinstalled I tossed out the entire T Bird folder, I never found any "Profiles" folder in it. Even now, see the capture of that folder, I even did a search. But by doing an "Everything" search of entire computer I did find such a file in "Users>AppData." See the 2nd capture, that subfolder in it is the only one there. Is this the folder I am not supposed to throw out? I didn't. As I said, I had thrown out the entire Thunderbird folder, restarted, reinstalled, restarted and worked fine until the next time computer started up. I will follow your instructions. Thanks again.

Ok, it seems to have worked over several days and start ups. I did get some message I failed to save, something to the effect that the updater failed to run, but it is working fine, thanks.

I was able to solve the 'xpcom missing error' I got for a long time as Thunderbird wouldn't start when my computer started.

Open the 'Task Manager' on the menu by right clicking in Windows 10 task bar, next to the empty space on the bar showing the time and date.

On the task manager menu top menu click startup, right click on Thunderbird and select "Open File Location". If the File Explorer opens on C:\Users\(Your PC Name) \AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup, delete the Thunderbird file there.

Then, open in File Explorer the C:\Program Files (x86)\Mozilla Thunderbird directory. Find the application Thunderbird (.exe) and right click on it. Click "Create Shortcut" and confirm to place the shortcut on the desktop. Cut paste the Thunderbird - shortcut file from the desktop to C:\Users\(Your PC)\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup.

This worked for me after trying all the options of deleting and install/uninstalling the software and registry etc.

If any help on above kindly email me on [email protected]