However, sometimes trying to access the servers or applications, the user can run into the PuTTY X11 proxy: Unsupported authorization protocol error. This error can be caused by a number of reasons which include:
Wrong ownership of the Xauthority file (and Locked Files)Corrupt Xauthority fileInvalid configuration of PuTTYIncorrect authorization settings FirewallX11forwarding is not configured in SSH config
This article demonstrates the methods to solve the unsupported authorization error for PuTTY.
Solution 1: Change Xauthority file ownership
The Xauthority file is the main component to use PuTTY because this file stores the cookies and credentials for the Xserver for the purpose of connection authentication. An unsupported authorization protocol error occurs when the Xauthority file is missing or the user is not the owner of the file. Let us follow the steps and solve this error.
Solution 2: Replace Xauthority corrupt file
In some cases, the Xauthority file can be corrupted and due to that, access to the server is not authorized. To solve this issue you will need to do the following steps The above output shows that it is necessary for the user to have control over the Xauthority. Note: Restart your machine and PuTTY connection for the changes to take effect.
Solution 3: Reconfigure the Invalid configuration of PuTTY
Setting up your PuTTY is also essential and sometimes, users make mistakes while configuring or setting up their PuTTY. To solve this basic error, follow the steps provided below:
Solution 4: Allow Firewall configuration for port 22
To use the X11Forwarding and PuTTY, you will need to configure the Firewall and enable Port 22. Here, the UFW utility is used to configure the Firewall: As you can see you have successfully set up PuTTY and accessed the server.
Solution 5: Configure X11Forwarding in SSH Server config
Another configuration error due to which PuTTY X11 authorization is denied is the invalid configuration of the SSH server. To configure the SSH server you will run the following command in your terminal. You have successfully resolved the error and gained access to the remote server. The PuTTY X11 proxy: unsupported authorization protocol error is where you can’t gain access to the remote server using PuTTY. The reasons for this error to occur have been mentioned in this post along with their solutions.
