My Windows 8.1 64 bit has been crashing with the message SYSTEM_SERVICE_EXCEPTION asw.Snx.sys This has happened quite a few times now, but I only noted message down today and thought to look on the internet to see what it meant, and came across this thread.
I use Avast Internet Security. I’m not up on techy things, and don’t understand the previous posts.
Can anyone help me please?
I having this problem ever since I went windows 8.1 - random thing but frustrating as hell. A few days ago I uninstalled my Avast free version and downloaded and re-installed the latest version - good for a couple of days and it just got the BSOD a few minutes ago. This has been reported for over a year with AVAST and no solutions - what gives with Avast support - time to get rid of this product and go to something else!
I’m running the Pro version of AVAST on a Lenovo running Win 7 64 bit. About 2 weeks ago I started getting BSOD and, after some blue screen diagnostics, aswSNX.SYS is top of the list! BSOD were twice a day and were getting very annoying.
Uninstalled AVAST and now running Microsoft’s MSE - no BSOD for over a week now.
The reason I bought AVAST was it looked good and had good reviews. Sadly I now seem to have wasted my money.
Is there any real solution to this apart from “reinstall and switch off the sandbox”?
Like Caminiano, I’ve scrapped my subscription to Avast and now rely on MSE - end of BSODs - Eureka!
Avast, don’t you care that I will tell everyone I can to AVOID AVAST ???
OK…I may get blasted for this & I want to go on record I am NOT an expert, nor have any direct knowledge.
However, I’m a very techy person and have been reading this Forum daily since Avast9 came out…waiting/hoping for “me” to update from Avast8 across all PCs…just have one test PC running now.
Anyway, from my readings I understand that aswsnx.sys is the Avast Virtualization driver.
It is linked to Sandbox and one of the options that seems to have helped is to uninstall Sandbox feature.
For my two cents, everyone can determine for their own, I do a CUSTOM install and I’ve just enabled A/V shields…meaning I uncheck all other options.
I only use Avast as A/V with supplement of active shields from MBAM Pro…both run nightly scans.
Thus, “for me”, all these other features/programs…GrimeFighter, AOS ,etc. are of no use.
I only mention the above because it sounds like Avast is working out some of these items.
In the meantime, one option to see if it has effect/solve.
Go to Control Panel > Programs and Features
Select Avast
In the menu on the left select CHANGE
Remove the tick from Sandbox and then press continue.
On reboot you can decide, or not, to enable Avast hardened mode…if so…set to “aggressive” to replace the sandbox function.
So what you’re saying is that you think it’s the Sandbox causing the problem.
Avast, are you reading this? Can you not do something to correct the problem? After all, you are the experts.
Thanks thekochs. I’ll try your suggestion.
Although I have to say that I like the idea of the Sandbox running, but not if it causes my laptop to crash when it feels like it.
What I am saying is I am no expert and do not know the inner workings of Avast…only Avast knows that…so me stating what “is” or “is not” the problem is not only wrong…but also misleading. However, it is well documented in the Forum that aswsnx.sys is the Virtualization driver. I personally have had the experience on other software packages where virtualization caused issues…good examples is backup imaging software that tries to backup you system while you are still using it. I’ve seen bad virtualization drivers cause many BSODs in this example. So, my point is that this is something to try and see if it makes an impact for you.
IMHO you still have the Avast “Shields”…Sandbox which I agree is nice feature…but if causes BSODs then not so worth the benefits.
I also have not installed Avast’s “Browser Protection”…again this not the Avast internet shields but what is known as AOS…a browser add-on.
This also has caused various issues for people thru their browsers…the suggestion has been is to disable the AOS plugin…I just don’t install.
So, for me I am still on Avast8 except one test system…which I’ve backed down to just “shields” from custom install…which for my one W7 64-bit machine seems solid. The problem with all this is for every one bad post/thread there are so many that do not have issues…so statistically this becomes not relevant…but, it is relevant to the person with the issue…SO, that is why I posted the suggestion. I hope it helps and will be interested to hear your results.
Lastly, if you are concerned about not having Sandbox then enable Hardened mode and set to aggressive…kind of a similar function/fallback.
However, do some reading on Hardened mode…some people like it…some do not.
On the positive side I have used AVG, Avira, Windows Defender, Symantec, McAfee…and Avast is still the best IHMO.
Avast 9 still is in its improvement stages but has come along way since Fall/2013 when first released.
I personally trust the Avast team…else I would have bailed along time ago.
Well I’ve disabled the Sandbox, so time will tell. . .
Thanks for your help thekochs. 
No problem…favor to ask…please post back (I assume you will if you have BSOD) but also if you have none.
I think many would like to know the results and if this truly had a positive effect.
Yes, will do. I’ve marked it in my calendar to remind me, in a month’s time. When/if it doesn’t happen, I might forget! :o
Good quick summary/post on Hardened Mode: http://forum.avast.com/index.php?topic=142172.msg1032485#msg1032485
Thanks for that thekochs . I’ve enabled Hardened Mode now.
No BSOD so far .
Hi, I have the similar problem, but my version of avast is free and don´t have the Sandbox option, in this place have “?”. My OS is Win8.1 64b.
As far as the “?” that is a good question…I thought you could uncheck Sandbox in FREE ?..perhaps Sandbox is not in FREE ?
You say you have “similar” problem…and using FREE…you are specifically getting BSODs and you are sure they are aswsnx.sys related ? If so, how do you know ?..e.g. dump file you used util to see, etc.
Perhaps one of the Sr. folks will post.
So it’s a month later, and no more BSOD. Thank you for your help thekochs.
I’m using windows 8.1 64bit and haved bsod caused by driver aswSnx.sys , caused by address aswSnx.sys+37ad .
This is my first bsod on this system.
I’m getting this BSOD in my latest avast as well !
It actually totally lock down my PC, crashes every program, lag out vred, PS, Vue, 3ds max and other softwares. Makes my life a living hell !
I already was on Hardened mode - Agressive.
Not helping. My PC just lock down and programs crashes. Specially when in the morning I come back to PC and do anyting it goes down badly. Is there another way I can fix the issue?
This problem started to happen ONLY when I installed new GPU, Titan X EVGA SC. Before I was on GTX 680 everything was fine. Also I did reinstall windows etc etc. Any one any help please?!
I have had this happen too. I have freshly re-installed win7-64 after a disk failure.
After all the installs and updates and shuffling about backup files I decided to do a defrag. While this was running there was a BSOD:
The problem seems to be caused by the following file: ngvss.sys
SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
etc…
and a few hours later, after restarting, another BSOD:
The problem seems to be caused by the following file: aswSnx.sys
PAGE_FAULT_IN_NONPAGED_AREA
Avast is a fresh re-install with no changes to settings.
Is there a general area to investigate for this?