Dunning data is not getting genrated

Hi Frnds,

Can any one please help me out in dunning procedure.

I m trying to create a spool using F150 and I am getting the followig error

"No change of dunning proposal , no dunning notice , No Dunning data genrated".

Though I have checked that dunning notices do exists as I was working on them few days back.

Thanks in advance.

Regards,

Khushy.