---
title: VcXsrv: Authorization required, but no authorization protocol specified
date: 2021-04-11
summary: X11 apps from WSL refused to open on a VcXsrv display with "Authorization required, but no authorization protocol specified". Relaunching VcXsrv with "Disable access control" ticked fixed it.
tags: x11, windows, wsl, vcxsrv
environment: Windows 10; WSL2; VcXsrv
author: shaun
status: published
aliases: Authorization-required-but-no-authorization-protocol-specified.html
---

## Symptoms

Starting an X11 program from WSL2 against a VcXsrv X server on the Windows side failed with:

```text
Authorization required, but no authorization protocol specified
```

## Cause

VcXsrv's access control rejects the connection, because WSL2 connects over a virtual network
and does not have a matching Xauthority cookie.

## Fix

Quit VcXsrv and start it again with **XLaunch**. On the *Extra settings* page tick
**Disable access control**. Programs then connect normally.

This lets anything that can reach the port open windows on your display. Keep the Windows
firewall rule for VcXsrv limited to private networks.