Can't send emails through Thunderbird

[REDACTED]

Everytime I send an email using Thunderbird, I get the message from avast saying it can't be sent because of the file /C:/DOCUME~1/HP_ADM~1/LOCALS~1/Temp/nsemail.html

If I send it through anyway, it goes to the person without the email - so it is blank.

I have to stop the shield and then then send it. I've tried adding
C:/DOCUME~1/HP_ADM~1/LOCALS~1/Temp/nsemail.html and
C:/DOCUME~1/HP_ADM~1/LOCALS~1/Temp/nsemail*.html
to the exclusions, but that does not help. How do I fix this so I can send emails. What is the affect if I permanently deactivate the shield?

[REDACTED]

I had exactly this problem when I updated Avast 2015.10.2.2015 to Avast 2015.10.4.2233 on a Windows XP SP3 system with the Mozilla Thunderbird 38.3.0 email client.  Reverting the the older Avast fixed the problem.

[REDACTED]

Thanks for your suggestion. If I revert back to the old version, won't I lose some of the protection? and how would I revert back to it?

[Eddy]

I suggest a clean installation of the latest avast beta version and see if that solves the problem.
Make sure you have the certificate exported/imported correctly as has been explained before.