1532496 - Cannot import XSD of exported IDoc in ESR

When importing a *.xsd or *.wsdl file as an External Definition in the Process Integration (PI) Enterprise Services Repository (ESR) you get the following error message:
Name contains invalid characters: .
Only a(A)-z(Z), 0-9, and "_" are permitted

• PI Release Independent
• SAP NetWeaver
• SAP Process Integration

Process Integration 7.0, PI 7.0, PI 7.01, PI 7.02, Process Integration 7.10, PI 7.10, Process Integration 7.11, PI 7.11, Process Integration 7.30, PI 7.30, Process Integration 7.31, PI 7.31, Process Orchestration 7.4, PI 7.4, PO 7.4, Process Orchestration 7.5, PI 7.5, PO 7.5, XI, AEX, XML , KBA , BC-XI-IBD , Integration Builder - Design , Problem