DP to SNP

I have the need to send a "raw milk collection" forecast from DP to SNP to a CC (stock) category. When I try this, the system displays the following warning: "Target category should be from category type 3".

As this message is warning I press the Ok key and the system displays the error:

"Error for COM routine using application program (return code 390)".

SAP says it is possible.

Has anyone done this before?. How can I work around the problem?

Thanks in advance!

-Italo