the plugin is already connected, and another connect request was received
the plugin is already stopped, and another disconnect request was received
the operation could not be performed as the request contained malformed arguments, or arguments of unexpected type. Usually means that one of the VPN setting data items or secrets was not of the expected type (ie int, string, bool, etc).
unknown or unclassified error
the operation could not be performed as the plugin does not support interactive operations, such as ConnectInteractive() or NewSecrets()
the operation could not be performed because the connection was invalid. Usually means that the connection's VPN setting was missing some required data item or secret.
a child process failed to launch
the plugin is already starting, and another connect request was received
the plugin is already stopping, and another stop request was received
the operation could not be performed in this state
Returned by the VPN service plugin to indicate errors. These codes correspond to errors in the "org.freedesktop.NetworkManager.VPN.Error" namespace.