SNP to PPDS order conversion

Hi,

I am trying to do small testing over PP run in SAP APO.

I have created everything manually in SAP APO(Product,location,No source of supply at Plant)

When running SNP at plant getting planned order without source of supply.Now i am trying to convert the same order into PPDS order using program(indicator is set).

Getting the below error:

"In-house production 188401198 is not valid for the conversion"

Any suggestion if this conversion is posible?

Thanks,

Krishna