APO Planning Calendar error /SAPAPO/CAL404

Hello friends, I am working in the transaction /sapapo/calendar trying to change a Planning Calendar and when I try to Calculate the periods in the view "Calculation Rule" i got a error message saying: Factory calendar TU not found (message number /SAPAPO/CAL404).

I have looked into SCAL transaction and the factory calendar is OK created and valid.

Thank you very much in advance.

Regards.

Ricardo Pereira