In my BusinessObjects there are two fields that initially will be null. The fields are CREATED (DATE) and CREATED_BY (Char). In the Business Object Mapper these have been set to "Return Alternate On Null". The CREATED has the NULL replacement set to System.DateTime.Today. CREATED_BY has the same value set to String.Empty.

When compiling the application the following error is returned:

For the CREATED field the error message is

Error 1 Class 'Field_CREATED_Descriptor' must either be declared 'MustInherit' or override the following inherited 'MustOverride' member(s):
    System.ComponentModel.PropertyDescriptor : Public MustOverride Sub SetValue(component As Object, value As Object). File: BO_CompanyDetails.Designer.vb

and for the CREATED_BY the error is

Error 2 Class 'Field_CREATED_BY_Descriptor' must either be declared 'MustInherit' or override the following inherited 'MustOverride' member(s):
    System.ComponentModel.PropertyDescriptor : Public MustOverride Sub SetValue(component As Object, value As Object). FILE: BO_CompanyDetails.Designer.vb 

Any ideas how to fix this?

TIA,
Kari

ps. Is it possible to have the  CREATED -field to be null rather than the  System.DateTime.Today (The dartabase would take care of setting the value in case it's null)