Configuration Error (PLCN0008): The OPC UA configuration is not valid. ...
The project contains an invalid configuration of the OPC UA server.
Possibly, the configuration is not done completely or with errors or the XML file storing the configuration is damaged or corrupted (does not comply with the OPC UA schema).
For example, the error is reported if 'Discovery registration = Enabled' is set but no valid 'Server URL' is yet entered (in the format opc.tcp://discovery.example.com:4840).
Double-click the error message to open the affected OPC UA Server editor and edit the affected field.
For further information refer to the topic "OPC UA Server".