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How to Fix “Valve Anti-Cheat was unable to verify that your machine is secure” in Dota 2

Dota 2 is a multiplayer online battle arena game that’s played by millions of players worldwide.

The game has regular updates on Steam with new gameplay, features, and heroes.

A hero can fill multiple roles and there are many items to meet each game’s needs.

All heroes are free, fans can collect cosmetics, and everything you need to play is included.

Team up with your friends and be matched with the right players based on your skill level in each game.

In this guide, you’ll learn how to fix “Valve Anti-Cheat was unable to verify that your machine is secure” in Dota 2.

What is VAC in Dota 2?

In Dota 2, VAC is short for “Valve Anti-Cheat”, which is a system to detect cheats on a computer.

If the system detects that a user is using cheats, they will be banned from playing the game.

In some cases, you may get a VAC error message by mistake.

This is because certain programs can conflict with the system.

This includes CCleaner, Powershell, Cheat Engine, IObit Start Menu 8, DLL Injectors, Hypervisors, and Steam Idlers.

You can try uninstalling or disabling these programs before launching Dota 2.

How to fix “Valve Anti-Cheat was unable to verify that your machine is secure” in Dota 2

To fix “Valve Anti-Cheat was unable to verify that your machine is secure” in Dota 2, try launching the game from Steam instead of the desktop app.

You can also try verifying the integrity of game files or uninstalling and reinstalling Dota 2.

Fix 1: Launch Dota 2 from your Steam library

  1. Instead of launching Dota 2 from the desktop app, launch it from your Steam library.
  2. Open Steam and go to your library.
  3. Select “Dota 2” and select “Play” to check if the VAC error is fixed.

Fix 2: Verify the integrity of game files

  1. Open Steam and go to your library.
  2. Right-click “Dota 2” and select “Properties…”.
  3. Select “Installed Files” and select “Verify integrity of game files”.
  4. Launch Dota 2 to check if the VAC error is fixed.

Fix 3: Uninstall and reinstall Dota 2

  1. Open Steam and go to your library.
  2. Right-click “Dota 2” and select “Manage”.
  3. Select “Uninstall” followed by “Uninstall” again.
  4. Reinstall Dota 2 and launch it to check if the VAC error is fixed.

Further reading

How to Fix CAppSystemDict in Dota 2

How to Fix Error 1114 in Dota 2

How to Fix Error 0x0000045a in CS2