Column Metadata cannot be set to Null

[novice_pgr]

Hi

When reading from CFF stage , i had set the Nullable Option as "yes" at the column level for Decimal data types. And the CFF stage was able to read the data. But today when i tried to repeat the same setting of Nullable to "yes" for the rest of the columns , it throws the warning "Column Cannot be set to Null Value" . I do not understand why all of sudden ?
Also , there was a DSclient installations done in some other machines during the intermediate time.
Is this a change in the project settings ?
Any help on this issue is much appreciated