The actual event entry is:

Event 20106 error:                              Source: Remote Access                              Category: None                              Description: Unable to add the interface Internal with the Router Manager for the IP protocol.                                            The following error occurred:                                           the parameter is incorrect.
To workaround this issue:

1. Administrative Tools / Routing and Remote Access.

2. Right-click the RRAS sever and press Properties.

3. Select the General tab.

4. If the server is configured for local routing only (LAN router), you can ignore this event. In local routing only mode, the IP Router Manager doesn't accept the internal interface, which is used to control the behavior of WAN interfaces that dial the network.