[ccp4bb] pROBLEM IN RUNNING dm

[Appu kumar]

Hello Dear all
                            I am trying running dm (density modification)
programe for density modification, but it giving error complaining about
density map. It says,  dm:   (WFO) No density in map! Check input FOM
present and nonzero.

Please suggest me how to overcome this problem. I am density modification
with SAD data , but dm giving error. Your help will be much appreciated.
Thank you
Appu