If a method call has an input argument that is a structure defined in a model library instead of a base OPC UA type, the server enters an endless tight loop. For example, I modified SampleDesign.xml to add a fourth input parameter to the CreateInstance method, using DataType="AddressDataType".

There are two problems going on:
1) The OPC UA server uses the contents of the Opc.Ua.Sample.NodeSet.xml file to validate the input arguments in the CoreNodeManager.Call method. In CoreNodeManager.Call the NodeId of the data type for the argument of type AddressDataType is ns=1;i=84, which is the same value as in the NodeSet.xml file. In the sample server though, the proper namespace index is ns=6. It seems that in the case of input arguments, the namespace index in NodeIds in ExtensionObjects is not being translated when read in by the server.

2) The TypeTable.IsEncodingOf method has an endless loop in
while (!NodeId.IsNull(typeId) && localTypeId != typeId)
Neither the localTypeId nor typeId local variables are modified in the loop so if the type or its direct base type is not a match then an infinite loop occurs.

The
m_server.TypeTree.IsEncodingFor(argumentDefinition.DataType, argumentValue)