Avast 17.4.2294 is slowing down Opera Windows 7 64-bit, 44.0.2510.1449 so very much that it becomes nearly unusable.
I’m using both Avast and Opera for many years without problems, this problem clearly came with Avast 17.4.2294. Now I have to shut down Avast in order to use Opera. Could you please fix this?
Perform a repair of avast.
If that doesn’t solve it, perform a clean installation of the latest avast version.
Thank you. Unfortunately both did not help, the problem remains also after a complete uninstall and reinstall. Opera works ok when Avast is disabled and gets terribly slow as soon as Avast is enabled.
BTW I’m not using the Avast VPN and Avast Browser-Add-ins.
Did you use avastclear when removing avast ?
Firefox 64 53.0 - OK
Chromium 64 58.0.3029.96 - OK
Vivaldi 64 1.9.818.44 - OK
Opera 64 44.0.2510.1449 - DISASTER (FileShield scanning Opera threads like crazy 0-100% CPU)
@Eddy: Initially not, but now I did. Thanks for this hint, but problem remains the same.
@Robert: Thanks for confirming this problem!
Disable the shields one at a time to see which one is the problem.
“File System” protection creates these problems. When this is switched off, Opera works fine.
The same. But… On home desktop pc with amd chipset and amd processor this does not occur. On 2 laptops with intel chipset and intel core 5/7 opera lags insanely…
Thanks!
That slowdown seems to affect Chrome browsers. I have 5 computers, 4 running Windows 10 and one running Windows 7 and I have many Chrome browsers installed like Opera, Iron, Cent, Dragon and it takes about 5x longer to start and load pages with all of them ex: Iron opens in 1-2 seconds normally now it takes about 10 seconds to get it to open and to load pages. The problem comes from File System Shield because when disabled they open really fast. It doesn’t seem to affect Firefox or Edge.
After turn on “nested virtualization” Opera speed is back to normal.
Update: Sorry, but this was only one time speedup. All next launches are slow again. :-[
marcus, there is only one Chrome browser.
The others you mention are not Chrome.
They are using the Chromium engine which is entirely different from the Chrome browser.
If the engine is build by e.g. Volvo, it doesn’t mean the car it is used in is a Volvo.
Sorry for not having used the proper technical word, but did you get what I was trying to explain? If you did good for you, it doesn’t matter if I used the perfectly correct word, I wanted to get a point across. I don’t think I was discussing cars either but a problem with Avast File System Shield that is still causing slowdowns with CHROMIUM based browsers not only Opera (on all my computers) that wasn’t there before I updated to version 2294. Now carefully check if my wording is right and tell me if it is not. English is my second language by the way and it is not perfect. Have a nice day.
I confirm this since Avast update 17.4.2294.
It affects Chromium-based browsers (tested on recent versions of Opera and Vivaldi), but apparently not Chrome itself.
Opening a link in a new tab or loading a webpage from a different domain in the current tab now add a 3-4 seconds delay instead of being immediate like before.
Disabling the File Agent solves this. It looks like simply adding the browser installation folder and profile folder in exclusion list isn’t enough.
I had to try this. I installed Google Chrome just to check Vlavv post and he is absolutely right Goole Chrome is not affected by the slowdown. Maybe it’s a conspiracy…OH NO not another one…
Here the same problem with Avast Antivirus Pro 17.4.2294 and Vivaldi 1.9.818.44.
I use Vivaldi as my main browser and this is driving me crazy, the lag is so annoying…
I hope there will be a solution soon or I have to look for another virus software.
Probably not, as Avast Safe Zone Browser is also affected. 
I just tried opening Iron and Opera and it seems that speeds are back to normal…
In another thread someone from avast confirmed the problem and they are working on a fix.
Yes, again they need to fix something >:(
I can confirm this.
After new virus definition update everything is back to normal (for now).