Knowledge Management

Question:
Hi
I created planing calender and customised lot size calculation for "PK".
Modified material master with lot size "PK" and given planning calender as maintained . BUt not allowing to run MRP or MRPlist.
Error : Error determining planning periods for calendar PC2
any help is appreciated.
Thanks
Answer:
create periods in Xn MD26
Smile.....it can solve 50% of your problems.
Answer:
create periods in Xn MD26
I created periods in md26 already . still system error is same.
Please Can you be specific.
thanks