2214994 - ESI - Error: "Illegal syntax: API:Parameter ... has initial value" when creating a Service Consumer

When creating a Consumer Proxy in transaction SE80, or running the report RSSIDL_DESERIALIZE_DEMO the following error occurs:

• Proxy generation: error occurred
  Exception occurred in library handler
  Illegal syntax: API:Parameter MESSAGE has initial value.
  
  OR
  
  
• Illegal syntax: API:Parameter BINDING has initial value.

In rare cases the following error might happen for the same reason:

• Incorrect value: Unknown QName.

• ABAP Web Services
• SAP NetWeaver
• SAP NetWeaver Application Server for SAP S/4HANA
• ABAP PLATFORM - Application Server ABAP

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