Sp was it ccleaner, kaspersky or some other software that updated you to a Thunderbird version that Thunderbird would not have updated you to? The Thunderbird team made a decision to not update existing users at this time due to some issues with the release that affected upgrades. But you appear to have an upgrade. How did it happen?

I would also bet that your anti virus is the reason you are not getting emails. try disabling scanning of secure connections in that product.

Kapersky did upgrade the program - having them auto-update my apps has never been an issue and unfortunately I had no warning anywhere on Thunderbird that it would be a problem. I've disabled that setting now since it's caused an issue here. Unfortunately there's no rollback. I see in another thread that someone else did try downloading an older version of Thunderbird but that seems to cause issues for them so I have not taken that route.

No, it's not Kapersky's email scanning that is causing this issue. I have tried disabling Kapersky entirely and playing around with any and every app setting that could effect Thunderbird and it's still not picking up emails.

There has been a load of issues reported when an auto update has occurred and it is always some update software.

As something may have wrong awry, I suggest you uninstall Thunderbird then download and reinstall version 78.0.1 from this link. https://www.thunderbird.net/en-US/thunderbird/all/

Please report back on results.

I'd prefer not to do this unless it's a very, very last resort. I have hundreds of emails I don't want to lose, and given the bugs everyone is describing, installing the newest version still seems like a gamble.

I'm hoping someone might be able to illuminate me on if and when Mozilla might patch this so their program is operational again, or if I'm going to need to give up and find another email program.

re :cleaning with CC Cleaner.

I would advise against this as those types of programs have a habit of cleaning out files that contain information you need. They have caused so much hassel to many people. If you like using that program for other purposes, I suggest you make sure all Thunderbird folders and files are exempt from scanning/cleaning etc.

Is Kaspersky fully up to date?

Using an ethernet cable, as wireless may not work when performing this test, restart the computer in 'Safe mode with Networking', then start Thunderbird as normal and report back on results.

I have used CC Cleaner for 10+ years and Thunderbird for 5+ years and have not had problems. I really wasn't asking for advice on CC Cleaner, with all due respect. :)

Yes, Kapersky is up to date. Even with the auto-update for apps turned off it does update its own files routinely.

Safe Mode does nothing to solve the issue. Thunderbird still hangs once it gets to "checking mail server capabilities." My laptop does not have Ethernet ports and I have a hotspot, so the only way to test anything is with wireless. The hotspot is already connected to the laptop via USB and Thunderbird still doesn't work.

Once again, I'm asking if Thunderbird has any intention of patching this. This isn't an error caused on my end. When a program works for years and an update suddenly causes it to stop working I should not have to spend hours unraveling whatever damage the devs did.

Try as test: In Account Settings > Server Settings for account Change Connection security: None.

Please report back on results

What errors are there in the Error console Tools > Developer tools > error console

Do you see anything that start like : ssl_error If yes, please post image of error console info

What ports and connection security are you currently using ?

In Help > Troubleshooting Information In Mail and News Accounts section Please copy all that section and post info into this forum question.

In Kaspersky is there an option to disable "Encrypted Connections Scanning" ?

Yes, that setting is in Network Settings, and it's already set by default not to scan encrypted connections. Kapersky is also set to only monitor certain ports.

I have also looked into other settings on Kapersky that could possibly affect Thunderbird. I've checked that it and Mozilla are on the whitelist as allowed programs, removed every entry for Mozilla and Thunderbird from the whitelist and then added them back, refreshed the whitelist, turned off "scan messages," turned that back on, disabled interactive protection, turned that back on, made sure Kapersky wasn't filtering spam, and so on and so forth. Unfortunately regardless of whether I've disabled these settings or not, there is no change in Thunderbird's inability to retrieve messages.

Even when all Kapersky processes are shut down via the Task Manager, Thunderbird still does not work.

Anti-virus and firewall programs certainly can cause issues but considering that Thunderbird still won't work even when the entire program is disabled or ended, I am confident it's not the case here. While the program has continued to update its virus/malware tables, no settings on Kapersky were changed between the time Thunderbird was operational and when it stopped receiving mail, and it's the same version of the program.

Thank you for the questions.

It appears that the 78 update made some registry changes. Part of the error log is cut off in the screenshot but the same error code (Component returned failure code: 0x80520001 ) keeps repeating.

[Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19

   loadSync resource://gre/modules/L10nRegistry.jsm:658
   fetchFile resource://gre/modules/L10nRegistry.jsm:573
   generateResourceSetSync resource://gre/modules/L10nRegistry.jsm:478
   map self-hosted:240
   generateResourceSetSync resource://gre/modules/L10nRegistry.jsm:473
   generateResourceSetsForLocaleSync resource://gre/modules/L10nRegistry.jsm:415
   next self-hosted:1099
   generateBundlesSync resource://gre/modules/L10nRegistry.jsm:177
   next self-hosted:1099
   touchNext resource://gre/modules/Localization.jsm:167
   regenerateBundles resource://gre/modules/Localization.jsm:552
   activate resource://gre/modules/Localization.jsm:243
   <anonymous> resource:///modules/calendar/calCalendarDeactivator.jsm:10
   <anonymous> chrome://calendar/content/calendar-chrome-startup.js:25

The only entry in the log that is not red: Successfully loaded OTR library libotr-5.dll from C:\Program Files (x86)\Mozilla Thunderbird\libotr-5.dll OTRLib.jsm:43:13

I've got STARTTLS and use port 143, which is what my email provider requests us to use for IMAP. I've tried toggling the password from encrypted to normal and from STARTTLS to SSL/TLS with no luck.

Suggest you try:

• Port 143
• Connection Security : none
• Authentication method: normal password.

who is email provider ?

That actually worked - and it also erased every single folder except for my inbox. I don't even have my 'sent' folder anymore. This does not improve things and I have now lost hundreds of emails I needed.

Aside from losing several hundred saved emails, it has not solved the problem overall because I'm not using a client that transmits passwords insecurely with absolutely no connection security. That's a compromise or a hack waiting to happen. And in all the years I've used Thunderbird it has never been necessary to do that.

I am not comfortable sharing my email provider with a stranger on a public forum. I have already confirmed with my ISP that there is no issue on their end and their web-based mail is working fine.

Whatever they did with 78, if it is only operational with zero connection security it is not a viable program to use. Not in 2020.

And I do apologize if I have sounded upset, I've tried to edit that out - but losing literally hundreds of emails has created even more issues and the program still cannot be used. At this point I think I'm going to stop attempting to do anything and hope that they recognize there are some issues and patch this eventually. In the meantime I'll have to go to Mailbird or somesuch.

Try this

• 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

As I said way back at the beginning of this topic the problem will be your anti virus. Kaspersky breaks the SSL process with self issued SSL/TLS certificates. I think I can almost guarantee that that is the cause of your issue. But as you have done nothing to check that I am still guessing it is the problem. Thunderbird 78 checks the validity of SSL certificates and the self signed ones always fail the check because there is no issuing server to check them with. Automatic failure.

But then when you do dodgy things like issue your own certificates or tell lies in your job application trouble can only occur when someone rings to validate the information.

Try this

• 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

As I said way back at the beginning of this topic the problem will be your anti virus. Kaspersky breaks the SSL process with self issued SSL/TLS certificates. I think I can almost guarantee that that is the cause of your issue. But as you have done nothing to check that I am still guessing it is the problem. Thunderbird 78 checks the validity of SSL certificates and the self signed ones always fail the check because there is no issuing server to check them with. Automatic failure. But then when you do dodgy things like issue your own certificates or tell lies in your job application trouble can only occur when someone rings to validate the information.

You're obviously not even reading my posts if you think I have not checked this. I DID. I DID BEFORE I POSTED HERE.

1. I HAVE USED SAFE MODE. IT DOESN'T HELP. 2. I HAVE COMPLETELY SHUT DOWN KAPERSKY. IT. DOES. NOT. HELP. 3. I HAVE RUN COUNTLESS TESTS AND TOGGLED SETTINGS IN KAPERSKY. ONE MORE TIME: IT. DOES. NOT. HELP. 4. I spent literally HOURS researching and testing this before posting here, I'm not an idiot that doesn't know how to check a &*(#&(#*(#* antivirus program FIRST.

4. As mentioned above, the only thing that DID help was changing Thunderbird's settings to absolutely zero security, AND BY THE WAY KAPERSKY WAS STILL ENABLED WHEN I DID THAT!!! SO THE PROBLEM IS THE THUNDERBIRD PROGRAM.

Please do not reply to me again. Thank you.

Try this

• 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

As I said way back at the beginning of this topic the problem will be your anti virus. Kaspersky breaks the SSL process with self issued SSL/TLS certificates. I think I can almost guarantee that that is the cause of your issue. But as you have done nothing to check that I am still guessing it is the problem. Thunderbird 78 checks the validity of SSL certificates and the self signed ones always fail the check because there is no issuing server to check them with. Automatic failure. But then when you do dodgy things like issue your own certificates or tell lies in your job application trouble can only occur when someone rings to validate the information.

Sorry Matt, but you're wrong. As shown above a) I know perfectly well how to use Safe Mode and it did nothing; b) No adjustments to Kapersky whatsoever did anything including shutting it down completely; c) the only way Thunderbird works now is to completely switch off ALL security in Thunderbird, NOT Kapersky, which had the added bonus of deleting all my folders except the Inbox.

Please don't reply to me again because you are obviously not reading my posts. Thank you.

I have this problem too. No solution yet.

Yes Kaspersky did do an update to Thunderbird. Since then everything from Fasthosts mail server stopped working. However my names.co.uk mail server continued to work oddly enough.

What did I try: I tested on a fresh install of Windows 10:

• v78: not working - connects, sends, but will not receive.
• v68: works fine.

A copy of the error log is attached. Looks like the code is trying to read a 'null' URI.

And yes, I've tried reinstalling v78, but that did not help. I've also tried reinstalling v68, but it complains the profile is not longer compatible. So it looks like I'll have to wait for a fix to arrive on v78. I dare not try to 'export from v78 and importing ato v68' with an add-on for fear of messing up years of emails.

I have this problem too. No solution yet.

Yes Kaspersky did do an update to Thunderbird. Since then everything from Fasthosts mail server stopped working. However my names.co.uk mail server continued to work oddly enough.

What did I try: I tested on a fresh install of Windows 10:

• v78: not working - connects, sends, but will not receive.
• v68: works fine.

A copy of the error log is attached. Looks like the code is trying to read a 'null' URI.

And yes, I've tried reinstalling v78, but that did not help. I've also tried reinstalling v68, but it complains the profile is not longer compatible. So it looks like I'll have to wait for a fix to arrive on v78. I dare not try to 'export from v78 and importing ato v68' with an add-on for fear of messing up years of emails.