Avast blocking internet access?

I have run Avast Free Antivirus for YEARS, on both my home computers (desktop and laptop(s)) and my computer at work. Never had a problem with it until a couple of weeks ago. Suddenly I had no internet access at work (home computers were just fine). I made NO changes to any of my settings. I could get email, I couldn’t SEND email, but I could get it. I re-booted a number of times and I’d have internet back for appx 5 minutes before it would go offline again. I reset our modem and router, I bought a new ethernet card, nothing helped. On advice from a friend I uninstalled Avast, and guess what? I had internet back! So no I’m running without any virus protection. I need virus protection, but I’m hesitant to reinstall Avast until I know this isn’t going to happen again… I’ve looked in the support section but find nothing about Avast disabling internet access. Anyone have any ideas?

I have run Avast Free Antivirus for YEARS
[s]What Avast .... Free or one with firewall?[/s]

Latest version?
tried repair and reboot?

Yes the free version, and yes, I tried to repair and re-boot–internet worked for 5 minutes then I showed to be off-line, tried a full re-set of my network and re-booted, same thing–access for 5 minutes then off-line

If Repair doesn’t fix the problem, try the following:
Clean Install of Avast:
https://goo.gl/4Ptzkf
If you need additional help with the Clean Install, watch this:
https://youtu.be/p-h3myRD51A

I’m having the same issue on my wife’s computer. Bought one before, ran into some issues (possibly due to hardware defect) so now we have a replacement. The other issues are resolved, but we ran with Win-Defender for about a week. Just installed Avast, and “eventually” we saw the internet connection was killed after some time (far more than 5 minutes). How do I know it was Avast? Because I disabled it and then the connection came back…

Again, it’s not frequent, but it’s annoying as hell.

Please don’t suggest “clean installs” or whatever, because I have tried those before with no solution. Besides, this is a brand new machine, just a basic minimal install, and nothing else. Again, the machine ran fine for a week or two without Avast, and had no issues… and the day after installing Avast this happens again. Admittedly, our general purpose machine (the one I’m typing this on now) is running fine again… don’t know what fixed it on here, but it doesn’t have the problem anymore. But, as posted before here https://forum.avast.com/index.php?topic=222690.msg1480467#msg1480467 it also had a problem.

Sounds to me like Avast is losing it’s quality… very disappointing to see…

Any REAL ideas or solutions are welcome.

What version of Avast ??? Free or Paid ??? What other Security software came with this new computer and how was it removed ???
You say that it happens on occasion maybe it’s time to check with your ISP to make sure you aren’t having problems on that end.

Avast Free

McAfee came installed on the machine originally. I uninstalled it via Windows, then rebooted, then ran MCPR to remove all traces of it, then installed Avast.

The older laptop, our two cellphones on Wifi, and our smart TV have no issues with the network connection when this new laptop loses the connection. As I mentioned we saw a similar issue with the old laptop before… and it just “fixed itself”… presumably because of a definitions update… but the new one had it the other day, as I mentioned.

Keep in mind, this is similar to the problem reported by the OP… clearly it’s not a unique issue.

Since the free version doesn’t contain a firewall, I highly doubt that the internet blockage is due to Avast.
It’s your Firewall that controls internet access.

Bear in mind, that:
A. This is a support forum and we get all sorts of issues reported some related to Avast other not.
B. Unfortunately the OP hasn’t got back to the forum despite suggestions in Reply #3.
C. If there is a conflict, disabling one part of the conflict will resolve the conflict, but not 100% identify the culprit.

For sure it is frustrating as hell.

Understood. But I’m still not getting any help to fix this… the connection dropped for my wife again today. I can’t expect her to troubleshoot this herself, so I don’t know how else to get this going. I’m thinking of removing Avast again, and seeing if that fixes it… that would prove that it’s an interaction on Avast. And, it’s frustrating to see this and not be able to troubleshoot it.

Again, I’m a LONG time user on various machines, and never had such issues… not sure what else to do. VERY disappointing.

Before you remove avast I would like to ask you if you have Malwarebytes installed on your computer.
My computer has also crashed today, after removing Malwarebytes it works fine again.

Nope… like I said, it was a clean, brand new machine. McAfee was the only thing installed, which I removed and MCPRed as well. Nothing else on the machine.

Software-wise, it currently has a subset of the software I have on my “main” laptop, which is working normally now (it had internet issues, as I mentioned, but they are now resolved). So, at worst, the new machine has the same software… yet it’s the one having issues. Of course, the hardware is different… but I need info on how to troubleshoot further to provide any real feedback. If someone can tell me what I can collect or test, I’m happy to do so…

Again just a few minutes ago - internet connection dropped out. Wifi still showed connected, but there was no actual connection (couldn’t get anywhere… even to devices on the home network, as the printer app pops up to show that it lost connection too, which is a sure sign of the issue). Disabled all Avast shields, and the connection came back. Re-enabled the shields and the connection remained working.

Again, is there any way I can provide logs or whatever to prove this is happening? Otherwise, I can’t imagine how Avast can fix this…

Reported to Avast. Let’s see if that helps.

Hi apurohit8,

does disabling only webshield help to resolve the issue? And when the connection drops, what is the CPU usage of AvastSvc.exe (in TaskManager - Details tab)? We released a defective VPS a couple of weeks ago (181113) that broke network connections and caused a high CPU usage (more info here → https://forum.avast.com/index.php?topic=223203.0). Can you make sure you are running a newer one and update it if not?

Jiri

Forgot to answer this one:

I have no firewall installed, other than what comes with Windows. The machine runs fine otherwise, but then stops suddenly and drops ALL connections. Disabling Avast “repairs” the problem… indicating that it’s related to Avast.

Also note that your statement of “it must be something else” is false, as noted by the reply just before this one, where a specific version of Avast caused high CPU usage and blocked internet access. Besides which, due to webshield (as noted there, too) Avast can certainly break the internet connection… since it’s watching what’s coming through.

CPU usage seems to be normal. I recall the issue before with high CPU usage and loss of network connection there (that’s what I experienced on my other laptop).

I will try disabling just webshield to see if that “repairs” the issue when it happens again. I wish it were more repeatable, so I have to let it happen again. Happens about every few days…

Hi apurohit8,

Thank you for the report.

If possible, could you please provide more details like:

  • The exact error message from the browser (ideally with info about browser version)
  • Does the issue appear immediately after enabling all shields (web-shield) or is it working for some time and then breaks?
  • Does ping of domain work or just ping of IP address?
  • Generate support package with debug logging enabled (Menu > Settings > General > Maintenance > Enable debug logging) when the issue appears and send us the ID: https://support.avast.com/en-ww/article/Submit-support-file

Thank you,
HK

There is no specific error in the browser.
The issue appears sporadically… I have to use the system a lot. Since it’s my wife’s machine, I don’t get to do this often… but I’ll try to collect logs and pings in the future (logging is now turned on, as requested…)

Still, to detail a bit more, the problem appears and then I disable all shields, then after about 15 or so seconds, the connectivity is restored. Note, again, this does NOT happen on our other laptop (older machine, Win10). I can then re-enable shields and the connectivity remains fine until the next random time that it fails.

I did check pings once in the past, and those failed as well. Network connection says I’m still connected to the router, but that there is no internet connectivity (according to windows, at least).

Remember, I also ran this machine without Avast for a few weeks (just with Windows Defender) and had NO issues during that time. Only after installing Avast did the problem crop up again.

Ok, just happened again after the first time. Please tell me how to find/forward logs. Where are they?

Ping fails, connectivity is lost (again, wifi shows connected to the router, but no internet). This time it’s not coming back even when I disable shields…

Tell me how/where to send logs and I can do it immediately. Note the time right now, as you may need it for the logs: Dec 25th, 2018, 6:28pm eastern time zone.