Analytics Software

I'm getting this error:
*Data source cannot be created : [MapperConfig] cannot add map data source.*

while following the step 2 of MapViewer Demo Setup tutorial.

I've the BI server installed on a machine and set up the schema for demo data on a RAC database.

I was able to set up the scheduler connecting via OCI and TNS,
but now when I try to add, from OracleAS MapViewer Admin, the data source MVDEMO I get that error.

I'm using:
NAME mvdemo
BASED ON: TNS is selected
TNS Name: ORCL_TAF
User: mvdemo
Password: mvdemo
# Mappers: 3
Max Connections: 100

Thanks,
Marco