Uniobjects - 40009 - Unable to convert

I have been trying to extract the data in a Universe system using
Uniobjects. For one field I get the error "40009 - Unable to convert
the data in the field". This is a "A" type field I am unable to use the
fieldnumber since it says it is an invalid field value,
Has anybody else encountered this before and
if so, what is the solution.

Thanks,

.