invalid security imap certificates

[dcdmetcalfe]

Using Thunderbird email client,i REPEATEDLY get a screen saying the Security Cert is invalid and asking to make and store a permanent exception.It refuses to accept this exception and the screen just repeats again and again til insanity sets in! The screen won't close or cancel. Thunderbird Forum says its the Avast mailshield (cert.issuer) and the Cert.Manager seems to confirm this. Following Avast Help procedures I tried to Export/Import the MailShield,but on trying to import into TB,it just says it already exists there. Can someone PLEASE help with this problem. I have Avast Free AV and the Avast Secure Browser.Both are completely up to date.

[Asyn]

- Which version of Avast Free..?
- OS..? (32/64 Bit..? - which SP/Build..?)
- Other security related software installed..?
- Which AV(s) did you use before Avast..?

[dcdmetcalfe]

Hi Asyn.Thanks for your time and reply. Windows 10 64 bit.  Avast Free,version 19.5.2378,build 19.5.4444.503. I also have Avast Secure Browser. No other AV's and have only used Avast AV

[Asyn]

1. Download Avast Free Antivirus: https://files.avast.com/iavs9x/avast_free_antivirus_setup_offline.exe
2. Follow instructions: https://www.avast.com/uninstall-utility (Run this tool for all prior installed Avast versions..!!)
3. Reinstall Avast with the downloaded installer from point 1.
4. Reboot.

[dcdmetcalfe]

Hi Asyn. You're a star!! Did as you said and,touch wood,no offending screen for 2 days. Thanks SO MUCH.!!

[Asyn]

You're welcome.