OPC UA PubSub Configuration Error (PLCN0038): '...': The ID of the writer must be unique within the connection.
In the configuration of the OPC UA PubSub communication, multiple writer Ids are specified. Within a connection, the writer Ids must be unique.
Using the combination of Writer ID, Writer group ID and Publisher ID, a subscriber identifies the publisher from which to read data.
Remedy
Open the properties editor of the affected writer group and define a unique Id for each defined writer.