Can anybody tell me how to change my email address in my account?
https://my.avast.com
add the new email address
set is as default
If you wish, you can than delete the “old” email address.
If I add my second email address as “new”, it seems to be accepted. But how to set this one as “default”? There appears no question about that.
Have you confirmed your new address ? Once Confirmed, you’ll be able to set it as the default and can also remove the old one if you want.
I don’t know if you can set it to default immediately after creating a new email address (as mentioned you may have to verify first) - if verified, try going back in on Manage Emails and select that new email and use the SET button to the right of the new email address to set it to the default.
If I input my new email address a popup window appears informing me that a link has been sent to my email address, and this email is empty.
It seems to be (made) impossible to change an account once connected with (google-) gmail.com to one connected with a non-ggogle email address. Right?
Reported to Moderator for help from Avast.
I also can’t get the confirmation email to add a new email address.
This wasn’t any problem in the previous version of Avast. 
It would be interesting if your new email address was a non-google address. 
It is. 
@ Gerd10
Bob has reported your problem, we avast users are limited in what we can do if the suggestions haven’t worked - we then try to draw attention to the problem.
Especially since, in this case, I have the same problem.
Fine! And in my case in the meantime I can’t use my Grime Fighter I have already payed for because I received its license through my second email address.