I am getting error message in Internal orders

Hi Experts,

Could any one help me on this

when i am posting an amount in cost element and taking old order and new order Manual reposting of internal orders (tcode: kb11n)

I am getting the below mentioned  error

Account xxxxxxx requires an assignment to a CO object                                                                              

Message no. KI 248    

Could you please me and please provide me extracts for this it will helpful

Thanks & Regards,

K Kali Praveen