CSGO (Counterstrike Global Offensive) is one of the most popular competitive shooter games. Since its inception in 2000, it has remained consistently popular due to its highly competitive nature and high skill ceiling.
Adding to its popularity is the fact that it’s free, making it one of the most easily accessible games around, but this comes with a catch.
As with any free game, it’s often the target of throwaway accounts that will use hacks or cheats to disrupt the gameplay of others. This makes it a high-priority target for antivirus software such as Avast.
If you’re encountering Avast blocking your CSGO game, don’t worry! We’re going to show you how to fix it.
Why is Avast blocking CSGO?
As CSGO is software that launches through another platform (in this case, Valve’s Steam client specifically), many processes are involved with launching the game that needs access to each other for everything to work.
That, coupled with the fact it’s a free and competitive game, means Avast can be very quick to jump in and block it should it believe something suspicious is going on.
Here are a few of the main culprits that will make Avast try to block the game.
Out of date virus definitions
As CSGO is a regularly updated piece of software, Avast needs to have its virus and malware definitions current and up to date to stand the best chance of working well with CSGO.
This is because if there is an update to CSGO or any associated software that Avast is unaware of, it may block the process.
Fortunately, Avast is very easy to update, and the process can be completed in just a few minutes.
Corrupt data or faulty installation
When Avast Antivirus or Firewall intercepts a process, mainly if this occurs during patching or updating of software, there is a high likelihood it will cause the update to fail and leave behind corrupt data or problematic Windows registry entries.
Fortunately, the Steam platform has an excellent and convenient way to check installations for inconsistencies. You can quickly sweep your CSGO game and ensure it’s installed and updated correctly.
Server.dll triggering quarantine
One issue users have reported is that after CSGO has been installed, Avast will try to quarantine the file “server.dll,” as it looks suspicious.
This file can be trusted, and we must manually navigate to the Quarantine Chest to tell Avast that this is safe and to add it to the Avast exception list.
Problems with associated processes in Steam
As we mentioned, when you launch the game, it’s not just CSGO launching. The Steam client needs to be working; there is the in-game overlay, graphics processes, and the Valve anti-cheat system.
All of these processes need to be whitelisted within Avast. If it blocks even one of them, you will not be able to play the game, and the anti-cheat will not be able to authenticate you as a trusted user.
Similarly, there is a lot of data about your machine that gets sent to the Valve servers to confirm that you are a legitimate user and not running any third-party programs that might compromise others’ play experience.
Avast’s firewall can easily interpret this as Valve “stealing” your data. Therefore, we need to instruct the Firewall not to be so overbearing and allow these processes to work before you are able to play the game.
How to stop Avast from blocking CSGO
We’re sure you’re eager to get back to playing, so let’s go through some straightforward fixes and tweaks you can make that will prevent Avast from blocking CSGO.
We will be adding some programs to the Avast whitelist here, but of course, Steam and CSGO are trusted sources, so don’t worry about putting your computer at risk.
Temporarily disable Avast
Sometimes these issues can be temporary. Maybe CSGO has issued a new patch causing problems, or Avast has recently updated its virus and malware definitions, which are awaiting a hotfix.
Regardless of the reason, a quick and easy way to get into CSGO without setting up more of a permanent solution is to right-click the Avast icon in the system tray and disable it for 10 minutes while you boot the software.
This gives you time to get in-game without putting your computer at risk for any prolonged time.
Update Avast’s virus definitions
Steam and CSGO are ever-evolving software, with Steam, in particular, adding new features almost monthly.
Avast is always trying hard to keep up with these software updates, as so many users have it installed on their machines. So if Steam or CSGO are suddenly causing problems, Avast may have already issued an update that lets Avast know they are safe and can be trusted.
Here’s how to update Avast’s virus definitions:
- Open the Avast software and head over to the settings.
- Click the General tab at the top, and then click the second tab titled “Updated.”
- Here you’ll be given two options; the bottom button will update the software itself, while the top will check that your virus definitions are up to date.
- Of course, it’s an excellent idea to ensure the software is up to date, but in this case, we need the top option.
- Avast will check to see if your virus definitions are up to date and if there is a new update. It will automatically download and apply it.
Whitelist “server.dll” in the firewall
Server.dll is responsible for establishing a connection to the CSGO servers, and Avast Firewall can very commonly see this as a malicious attempt to access your data and block it.
By adding server.dll to the Avast Firewall rules, it will know to ignore that in the future.
Follow the instructions outlined here to add a firewall exception within Avast.
Whitelist software in Avast Antivirus
Because Steam is an intrinsic part of CSGO’s functionality, handling all of the matchmaking and grouping functions, adding just CSGO by itself to the Avast Antivirus software whitelist is not enough to make it work.
We need to add CSGO and Steam to the list to work correctly.
Here’s how to do that:
- Open Avast Antivirus, navigate to the menu, and then the settings in the top right.
- Select the General tab at the top, and click “Exceptions.”
- Click “Add advanced exception” to target a specific file.
- First, add the primary Steam executable to the whitelist; by default, this is located at C:\Program Files (x86)\Steam\.
- Next, add the primary CSGO executable located at C:\Program Files (x86)\Steam\steamapps\common\Counter-Strike Global Offensive.
With both of these processes whitelisted, Avast will no longer be able to block CSGO from launching.
Verify the integrity of the game files
If adding virus exceptions for Steam and CSGO did not solve the issue, it may be a case where one of the files has become corrupted or there is an error in a Windows registry entry.
This can very commonly happen if Avast has intercepted a process during installation.
Fortunately, Steam provides a convenient feature to scan and repair any installation issues with CSGO. To do this, right click on CSGO in your Steam library and click on Properties.
This will create a new window for navigating to “Local files.” At the bottom, you will have an option called “Verify integrity of game files…” Click this, and Steam will automatically scan the game and fix any issues present in the installation and restore the game to working order.