Hello
Does anybody else have to Disable Free Antivirus 20.9.2437 to then be able to download emails using Thunderbird?
I am using the latest version Thunderbird - 78.5.1.
I love Avast and T’Bird, but something is not right between them.
Even if you have no problems between Avast 20.9.2437 and T’Bird 78.5.1. … please just say.
Thank You
EDIT/ PS
Wish I’d joined this Forum 3 days ago … would have saved me lots of frustration!
So thanks @r@vast!
I joined and searched the T’Bird Forum and one (at least) T’Bird Developer blaimed Avast! Cheek!? 
Here is the fix from another Topic. Works for me
[quote author=r@vast link=topic=231152.msg1529672#msg1529672 date=1576763657]
Hi,
Try to turn off IPv6 in Thunderbird and see if it helps.
Options/Advanced/General/Config Editor
Enter IPv6 in the search bar.
Toggle the setting to: TRUE