Hi! Sorry for my english, i’m still learning.
I change mi account password in my.avast.com. After that i try to do a smart analysis in one of my devices and i cannot.
https://drive.google.com/open?id=0B8uoI0i6uO50NnRSR05wTDBLUG8
Invalid password?
Please if someone can help me!!! Thank you!!! 
The password for your account and the password set on avast (the av) are two different things.
You need to use the password set on the av, not the one you use for your account.