The avast sidebar gadget has suddenly disappeared today, why?

have you tried to search the forum?
have you tried avast FAQ section?
have you tried avast repair?

I have just tried avast repair which didn’t work.
Can you give me the link to the FAQ section?

www.avast.com > support > FAQ … and in top right corner you can change language

also use search word video in FAQ section for how to do videos