VAN 138: Vanguard detected a virtual machine

Connection Error: VALORANT encountered a connection error. Please relaunch the client to reconnect.

The message hides the real problem

Nothing on screen says "virtual machine". Riot's error line for VAN 138 is a plain connection error, and it doesn't even carry the number (the wording differs slightly from the other connection errors, too, with "encountered" where they say "has encountered"). You'd reasonably start checking your internet. Riot's article says the cause is somewhere else entirely: Vanguard doesn't support virtual machines, and VAN 138 is what it throws when it believes it's inside one.

That rule isn't specific to this code. Riot's League article on the "your game requires a system restart" message says the same thing about VirtualBox, VMware and Parallels, warning the game may refuse to start or crash inside them. If you run League in a VM on purpose, no step below will change the answer; the only fix is a normal Windows install on the machine.

If you're sure you're not in a VM

Then Riot's remaining steps are your route, and they're a slightly different set from VAN 9100's, which shares the meaning but stops after a Vanguard reinstall. VAN 138 goes on to a clean boot, a firewall check and a game reinstall. The firewall step is the unusual one: no other VAN article asks for it. Riot's reason is that a firewall can block the Riot Client from talking to Riot's servers, so add exceptions for the client and the game before you reach for the full reinstall.

Riot's fix, in Riot's order

1. Run the game on Windows itself, not inside a virtual machine

   Vanguard refuses to run inside VirtualBox, VMware, Parallels or any other virtualized setup. The game and Vanguard have to be installed on a normal Windows install on the PC itself.

2. Uninstall Vanguard, restart, and let the game reinstall it

   1. Close the game and exit the Riot Client from the system tray.
   2. Right-click the red Vanguard icon in the tray, choose Advanced, then Uninstall Vanguard. If the icon isn't there, search Windows for Add or remove programs and uninstall Riot Vanguard from the list.
   3. Restart the PC. Vanguard is gone if its tray icon doesn't come back.
   4. Open the Riot Client and launch the game. It reinstalls Vanguard and will ask for one more restart before Play unlocks.

   Riot's guide: Uninstall Vanguard, restart, and let the game reinstall it

3. Do a clean boot

   This switches off every non-Microsoft service for one boot, so you can tell whether something in the background is the problem.

   1. Press Win+R, type msconfig and press Enter.
   2. On the Services tab, tick Hide all Microsoft services first (skip it and you'll switch off parts of Windows).
   3. Click Disable all, then tick vgc again so Vanguard still starts.
   4. Apply, OK, restart, and test.

   Some programs ignore a clean boot anyway, third-party antivirus and networking tools most of all. If the error goes away, turn services back on a few at a time until it returns, and you've found it.

   Riot's guide: Do a clean boot

4. Let the Riot Client through your firewall

   Add exceptions for the Riot Client and the game in Windows Defender Firewall and in any third-party firewall you run. Riot's firewall guide lists the exact files.

   Riot's guide: Let the Riot Client through your firewall

5. Reinstall the game

   Uninstall from Windows' Installed apps list with the Riot Client closed. For a clean reinstall of League, Riot also has you delete the Riot Client folder under C:\Riot Games, the Riot Games folders under %localappdata% and %programdata%, and the League of Legends folder in Documents. That last one holds your replays, so copy them out first if you want them.

   Riot's guide: Reinstall the game

Related errors

• VAN 9100
• VAN 9101
• System restart required
• VAN 133

Source: Riot Games Player Support, Error VAN 138, updated July 14, 2026. Riot's steps are paraphrased here, not copied; checked September 25, 2026.