How to fix "The WinRM client cannot process the request because the type field in the WSMAN ALLOWED PUBLISHERS argument is invalid."

Description

This error occurs when the Windows Remote Management (WinRM) service tries to parse the WSMAN ALLOWED PUBLISHERS configuration policy but encounters an incorrect, corrupted, or unsupported data type format. This group policy setting restricts which publishers are allowed to run remote management plugins. If the registry entry or the group policy object (GPO) pushing this configuration contains format errors, the WinRM client fails immediately and blocks remote management connections.

Step-by-Step Fix

Method 1: Clear the Registry Entry via Command Prompt

The fastest way to resolve this issue is to remove the corrupted registry key so WinRM can revert to its default, working state.

1. Press the Windows Key.
2. Type cmd into the search bar.
3. Right-click Command Prompt and select Run as administrator.
4. Copy and paste the following command into the window:

   reg delete "HKLM\SOFTWARE\Policies\Microsoft\Windows\WinRM\Client" /v WSMAN ALLOWED PUBLISHERS /f

5. Press Enter to execute the command.
6. Restart the WinRM service by running this command:

   net stop winrm && net start winrm

Method 2: Fix via Group Policy Editor

If your computer is part of a domain or uses local group policies, the bad configuration might be coming from a GPO.

1. Press Windows Key + R to open the Run dialog box.
2. Type gpedit.msc and press Enter.
3. In the left sidebar, navigate to the following folder path:
   • Computer Configuration
   • Administrative Templates
   • Windows Components
   • Windows Remote Management (WinRM)
   • WinRM Client
4. In the right pane, look for the policy named Disallow WinRM execution from unallowed publishers or Allowed Publishers.
5. Double-click the policy to open its settings.
6. Change the setting to Not Configured or Disabled.
7. Click Apply and then click OK.
8. Open Command Prompt as an administrator and force the policy update by typing:

   gpupdate /force

Method 3: Reset WinRM Client Configuration

If the error persists, you can completely reset the WinRM client configuration back to the factory defaults.

1. Open Command Prompt as an administrator.
2. Type the following command to reset the WinRM client:

   winrm reset

3. Type the following command to reconfigure quick access:

   winrm quickconfig

4. Press Y when prompted to confirm the configuration changes.