When working with OPCUA nad .NET you might get following error:
Opc.Ua.ServiceResultException: 'Invalid namespace index.'
This happen oviusly if the NodeId is not specified in correct format.
For example, following NodeId cannot be parsed:
ns=4,i=1274
In this case, error is missleading ';' instead of ','. Following is correct expression:
ns=4;i=1274