SAP Message RSAR179 - Invalid source sytem type

Diagnosis
The specified source system type is not valid. Permitted types of sourcesystem are:
@M1@ Own BI system
@6K@ SAP source system
@GH@ BI data mart system
@6M@ External system (PC file from workstation or file on application
server)
@6L@ External system with data transfer and metadata transfer using
BAPIs

Procedure
Specify a valid system type.