For me it has been a giant pain in the backside all day, some times I would get on, open a topic, reply but failed to post and got tons of Secure connection failed, etc.
I found out that this was caused by a Forum failed security update and the Software Authors (SMF) have/had to do something about it.
All in all yesterday/today it has taken well over 12 hours to get anything like a stable period.
During that time I checked out this frequently.
https://downforeveryoneorjustme.com/forum.avast.com Reports:
Forum.avast.com Status
Is forum.avast.com down right now?
It's not just you! forum.avast.com is down.
And it failed to post on this reply, so it still isn't stable, unable to post.
Back to try again 10am over 24hrs and still not stable.