I have a weird problem… Since some time (I think since 20th of June?) Avast can’t connect properly to it’s servers. Updating either virus definitions or the program fails at the download phase. Even installation fails (as I thought “maybe I’ll install again and it’ll go away”) - and it’s related to connection problems as can be seen in the log attached. I reinstalled from some offline instalator, but the problem persists there.
Interesting thing is when I try to log in through the program - it clearly connects somewhere, as it knows when I input incorrect credentials. But when I put in correct ones it thinks for a while and than says it couldn’t connect my machine to my account.
- Which Avast…? (Free/Pro/IS/Premier)
- Which version…?
- OS…? (32/64 Bit…? - which SP/Build…?)
- Other security related software installed…?
- Which AV(s) did you use before Avast…?
Avast Free, currently 17.5.2302 after install from offline installer (but was similar before, most likely stuck at a version that was up to date on 20.06).
64 bit Windows 10 Pro, updated today to creators update (though it wasn’t working before that as well)
I have Malwarebytes installed though not running constantly, CCleaner as well.
I used avast for the last 3 years on this machine, and longer on other ones, not sure why that’s relevant.
Repair Avast:
- Control Panel → Add/Remove programs → Avast
- Click on ‘Repair’.
- Follow instructions.
- Reboot.
No need for a repair or anything.
Change your DNS to the one from Google and it should work.
For some strange reason several of the avast servers can’t handle IPV6.
Hi Eddy,
where did you get this info from (link appreciated)…!?
If so, this needs to get fixed ASAP, IPV6 isn’t new anymore.
I’ve seen someone from avast mentioning it on this webboard, but only 1 time as if they try to hide this info.
But look at all the people whit the same error in the log.
Changing the DNS solved it.
I expect to see more and more people with the same problem soon as more and more ISP’s are rolling out IPV6.
I’ve asked avast several times to explain/add the 41227 error in the list with error codes but they are really quiet about it >:(
That was it actually! I turned off IPv6 in connection settings, and set my DNS manually to google ones (8.8.8.8 and 8.8.4.4) in IPv4 and magically updates work now, and I can log in
As I expected 
Well, I’m on IPV6 for a long time and have no issues here, there must be something else in the mix.
It can be your ISP is using a “fallback” to IPV4 is IPV6 isn’t working.
Sure, but doesn’t any ISP do that…!?
No.
Well, if so, my advice to the OP is to change his ISP.
In many locations, that’s not an option. 
You’re certainly right Bob, and I can only speak for my region (Europe).
I’ve reported this on the other channel hopefully Avast can do something about it.
Well, if this issue is ISP related, Avast can’t do much about it. But let’s see…
This is peculiar.
- If I run test-ipv6.com while connected via avast VPN (does not matter where) I have no IPv6 connections available. They all time out
- If I run standard test without running avast VPN, then I get IPv4 and IPv6 Teredo connections
- ISP I use has yet to fully update to IPv6 connectivity so Teredo is activated
So:
-avast VPN does not allow IPv6 connections
-standard no VPN connection allows Teredo IPv6.
It has nothing to do with the ISP but with avast.
If the ISP (still) uses IPV4 (only) there is no problem, but if the ISP is using IPV6 the avast servers can’t handle it.
That is why changing the DNS to the one from Google is solving the problem as Google’s DNS is using IPV4 (or fallback to it when IPV6 is not working).
As I said, I expect to see many more complaints about this.
My advise for all helpers, let the user check the log file(s) and if it shows a 41227 error in them advise them to change their DNS and disable IPV6 in the network properties.
This is ofcourse not a real solution, but it will the users to update etc without problems.
The real solution much come from avast.
They really should (as they say) get their act together.