String is required Here

Question

If {OPOR.TotalExpns} = 0 Then "NIL"
else 
 IF {OPOR.TotalExpns} > 0 Then {OPOR.TotalExpns}

Answer 1

The return value is different for each of the condition.

If {OPOR.TotalExpns} = 0 Then "NIL" 'here you are returning a string
else 
 IF {OPOR.TotalExpns} > 0 Then {OPOR.TotalExpns} 'here you are returning a number

This is what you could be looking for

 IF {OPOR.TotalExpns} > 0 Then CSTR({OPOR.TotalExpns})