Error: The ID of the writer group must be unique within the connection
In the configuration of the OPC UA PubSub communication, multiple writer group Ids are specified. Within a connection, the writer group 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 writer group Id.
Example