Hi Eva,
Could you please explain, what do you mean by Production Planned Orders? Did you mean ECC planned orders i,e, you could transfer them to ECC as a planned order?
There may be a chance for an error with your PPDS PDS. Could you please try to create a PPDS planned order from RRP3 and check if it is created without any error?
Also check the validity of your PPDS PDS.
Regards,
Manimaran M.