Error while accessing unpaid absence

Dear ,

i ' m creating an absence that deduct from the salary "unpaid absence", if the employee is absence for 3 days then the salary is deducted by 3 * hours rate of the day ...

In PA30 when creating " unpaid absence " for the user using infotype " 2001 - absences" i receive the following error

"Counting rule /B/00/.. does not exist"

so plz anyone could help ??