The valid data types for V_REPLACE() and V_RETRIEVE() are defined
   in the V_REPLACE() function reference.  If FlexFile encounters a
   type which is not amoung these valid types, this error will be
   generated. For example, using V_RETRIEVE() to try to fetch a Summer
   87 array will create this error. Use V_FILLARR() instead.

   In addition, if you make the mistake of using a pointer-field which
   points into one file as a pointer-field for a different file, FlexFile
   will again generate this error.  This is because the pointer-field
   is pointing to something other than the header which FlexFile pre-
   pends to each field.