OpenVPN Connect: Agent and Adapter Error Messages on Windows

This article addresses common error messages related to the OpenVPN Connect service and its required adapters on Windows. These issues are often related to missing or disabled drivers, services, or conflicts with other software.

TAP/DCO adapter is disabled

Error Message:

TAP/DCO adapter is disabled

Description:

This indicates that the TAP or DCO adapters are installed but currently disabled on your Windows system. A disabled adapter prevents the VPN from establishing a connection. This can occur if an adapter was manually disabled by the user or affected by a third-party application or system policy.

Solution:

To enable the TAP or DCO adapter:

1. Press Windows key+R to open the Run dialog.
2. Enter devmgmt.msc and press Enter to open Device Manager.
3. In Device Manager, expand the Network Adapters section.
4. Locate the TAP-Windows Adapter V9 for OpenVPN Connect and/or the OpenVPN Data Channel Offload adapters.
5. Right-click the adapter and select Enable device.

Important: If the issue returns, check for group policies or third-party software that might be disabling the adapter.

VPN Connection is being utilised by another Windows user.

Error Message:

VPN Connection is being utilised by another Windows user.

Description:

This occurs when another user on the same Windows machine has an ongoing VPN connection. Windows doesn't support multiple users sharing the same VPN adapter simultaneously.

Solution:

Ensure that no other user sessions on the machine have an active VPN connection using OpenVPN Connect. Disconnect any existing sessions before trying to connect again.

OpenVPN Agent service is not running

Error Message:

OpenVPN Agent service is not running

Description:

The OpenVPN Agent service is installed but not running. This service is required to establish the VPN connection with OpenVPN Connect. Causes may vary, but usually it's related to the service being manually disabled by the user or a third-party application.

Solution:

To start the service:

1. Press Windows key+R
2. Enter services.msc, and press Enter.
3. Locate and select the service named: OpenVPN Agent agent_ocpnconnect.
4. Right-click the service and choose Start.
   

Important: If the issue recurs, check for third-party software or policies that may be disabling the service.

OpenVPN Agent service is missing

Error Message:

OpenVPN Agent service is missing

Description:

This means the OpenVPN Agent service required by OpenVPN Connect isn't installed on your system. This may result from an incomplete installation or interference by security software.

Solution:

Reinstall OpenVPN Connect using administrative privileges:

1. Download the latest installer.
2. Right-click the installer and choose Run as administrator.
3. Complete the installation process.

Important: If reinstalling doesn't resolve the issue, we recommend checking if there are any policies or third-party software present on the Windows device that could tamper with the agent_ovpnconnect service.

TAP/DCO adapter is missing

Error Message:

TAP adapter is missing

or

DCO adapter is missing

Description:

The necessary drivers (TAP or DCO) are missing from the system.  Causes may vary, from initial installation issues to drivers being removed post-installation. 

Solution:

Reinstall OpenVPN Connect with administrative privileges:

1. Download the latest installer.
2. Right-click the file and select Run as administrator.
3. Complete the installation process.

Important: If reinstalling doesn't resolve the issue, we recommend checking if there are any policies or third-party software present on the Windows device that could tamper with the TAP or DCO drivers. 

Please submit a ticket if you have additional questions or are still encountering issues.