Hi,
To run CK11N first you enter your FG material and it's plant.
In Costing data Tab put your costing variant created in Config of OKKN t code
For date issue please check the config made for date control in OKK6 ( which also appears in OKKN)
As shown in your screen shot your date control is "Start of the month"So system give you warning message given below.
If you want do other module cycle on that material Run CK11N and change the date manually "Costing Date From" enter oday's date run run the CK11N and CK24.
Otherwise wait for next month to take costing run as configured ..
Regards,
Prasad