DNS_ERROR_VIRTUALIZATION_INSTANCE_ALREADY_EXISTS 0x800726C1

Error code 9921 · HRESULT 0x800726C1

WINDOWS

The virtualization instance already exists.

Windows troubleshooting diagram: Device Manager warning and a system file scan
Windows errors: check drivers, system files and Event Viewer, in that order.

What it means

DNS_ERROR_VIRTUALIZATION_INSTANCE_ALREADY_EXISTS is a Windows error code (system error 9921, returned as HRESULT 0x800726C1) reported by Windows. Its official message is: “The virtualization instance already exists.”

How to fix DNS_ERROR_VIRTUALIZATION_INSTANCE_ALREADY_EXISTS

  1. Test connectivity to the remote host first (ping, then the exact port)
  2. Check firewall, VPN and proxy rules for the involved process
  3. Run 'ipconfig /flushdns' and 'netsh interface ip reset', then reboot

Related errors

DNS_ERROR_VIRTUALIZATION_INSTANCE_DOES_NOT_EXISTDNS_ERROR_VIRTUALIZATION_TREE_LOCKEDDNS_ERROR_INVAILD_VIRTUALIZATION_INSTANCE_NAMEDNS_ERROR_DEFAULT_VIRTUALIZATION_INSTANCEDNS_ERROR_RRL_LEAK_RATE_LESSTHAN_TC_RATEDNS_ERROR_RRL_INVALID_LEAK_RATEDNS_ERROR_RRL_INVALID_TC_RATE

Source: Microsoft WinError.h

Last updated: