Derivation Rule Problem - Sales Order

Hi Friends

I am SD consultant, i wrote this issue on SD forum also, but it is related to FICO.

Please send me solution with complete path.

When i create a new sals order and click enter, a small screen open and message displayed on it "Error occured in Derivation Rule, Seee long text"

And when try to save sales order in display incompletion log. When i press on edit to complete it message diaplay " Item 10 ... Missing data- Profitability Segment No.

When i press on complete data - Account Assignment screen open (Business Area 9900)

Would you please send me solution to fix this problem

If you can give your email address, i will send you screen shot of the problem.

Thanks

Rajesh

Email: rksingh177@hotmail.com