[fixed] Blue Screen (BSOD) - Windows 10 Anniversary Update on Skylake CPU

[petr.chytil]

How to prevent and fix
All Avast installations should be patched now but in case you need a step by step help - https://www.avast.com/en-us/faq.php?article=AVKB272#artTitle

What happened (simple version)?
Avast Antivirus without Thursday’s patch + Windows 10 Anniversary Update + Intel Skylake with Intel VT on = BSOD.

What happened (in detail)?
On Tuesday, August 2, Microsoft released their latest version of Windows 10 - the Anniversary Update - via the Windows Update channel. While the majority of our users didn’t have a problem, certain HW configurations didn't mix well with the update. To be specific, when the Windows 10 Anniversary Update was combined with our aswvmm.sys driver on an Intel CPU from the Skylake family with Intel® Virtualization Technology (Intel VT) enabled in the BIOS, the update resulted in a BSOD. This occured during upgrades to the Windows 10 Anniversary edition from previous versions of Windows, and during clean installations of Avast Antivirus on systems already running the Anniversary Update.

When was it fixed?
For a better insight into what was patched and when, please see the following timeline.

Timeline (CEST):
Aug 2 8PM - Window 10 Anniversary Update starts rolling out
Aug 3 1AM - First mention on forum about the BSOD
Aug 4 8PM - Emergency update released for Avast 12.2.2276 - clean online installations are fixed
Aug 5 9AM - Emergency update released for Avast 12.1.2272, 2016.11.2.2262, 2016.11.1.2253, Avast for Business 12.1.2512, 11.2.2511
Aug 5 9PM - Avast Emergency update is scheduled to run every 12 hours or about 10 minutes after system startup.
All above mentioned versions should now be patched.

Is Avast Antivirus compatible with the Windows 10 Anniversary Update?
Yes. For the time being, however, please don't perform installations using offline installers without an internet connection. We will update offline installers later.
Update: Offline installers of Avast Antivirus 12.3.2279 already contain the fix - https://forum.avast.com/index.php?topic=189836.0

Why was the incompatibility not discovered sooner?
We're still investigating the answer to that. Neither the Windows Insider program nor the Avast Antivirus Beta channel indicated any forewarning of such behavior.

Thank you!
We're very thankful to our Avast users especially those who posted here on the forum! You helped us discover the root cause much faster which drastically sped up our delivery of the fix.

Have a good day,
Petr

[RejZoR]

I like the openness and verbosity of these reports (these forum stickies) when issues arise. It shows you guys are stepping up the QA game. I like it.

[REDACTED]

A true indicator of character is in how one handles crisis under stress.  Back-to-back fires handled with professionalism.  Another job well done, your team deserves a break!

[Gopher John]

I like the openness and verbosity of these reports (these forum stickies) when issues arise. It shows you guys are stepping up the QA game. I like it.

I agree. I like the way they owned it and moved quickly to address the problem, all the while keeping us informed.  This shows a very high level of integrity and devotion.

[REDACTED]

Thanks for the quick update!   

[adamchamney]

Thanks for all the info and all the help petr.chytil in getting my PC back up and running!
Microsoft can learn a lot from you guys!

[REDACTED]

Awesome support. Thank you!

[REDACTED]

I had to uninstall Avast in order to update my Skylake CPU computer. I am running Defender at the moment  as I am unclear as to where I should download the patched version to install Avast again. Can someone explain where this is located? The filename on the version released a few days ago which caused the problem do not reflect, as least to, me to be the patch version.    Thanks for any help.   

[Alikhan]

I had to uninstall Avast in order to update my Skylake CPU computer. I am running Defender at the moment  as I am unclear as to where I should download the patched version to install Avast again. Can someone explain where this is located? The filename on the version released a few days ago which caused the problem do not reflect, as least to, me to be the patch version.    Thanks for any help.   

Hi,

Just download and install your version - these online versions have the patches included.

http://files.avast.com/iavs9x/avast_free_antivirus_setup.exe

http://files.avast.com/iavs9x/avast_pro_antivirus_setup.exe

http://files.avast.com/iavs9x/avast_internet_security_setup.exe

http://files.avast.com/iavs9x/avast_premier_antivirus_setup.exe

[Be Secure]

Good work Avast! team. :)Keep us updated like this.

[REDACTED]

What happened to Browser protection? Is it replaced by Browser Extension? Also what is Antispam? Thanks to anyone who can explain these.

[DavidR]

What happened to Browser protection? Is it replaced by Browser Extension? Also what is Antispam? Thanks to anyone who can explain these.

Please don't post the same question in multiple topics thanks.

I have answered earlier question, https://forum.avast.com/index.php?topic=189131.msg1330654#msg1330654.

[Ch3vr0n]

This issue may not be fully fixed. See my last post https://forum.avast.com/index.php?topic=189403.msg1330690#new

[bob3160]

This issue may not be fully fixed. See my last post https://forum.avast.com/index.php?topic=189403.msg1330690#new

Since your system is clearly not a Skylake CPU, it has nothing do do with this issue. This issue has been fixed.

[Ch3vr0n]

maybe not, but those drivers with a numeric sequence are related. They were mentioned in the first issue too, so it might very well be related.