Forms or Form classes that specify a DEClass and DEClassLibrary cannot be converted to or used with a FormSet. (Error 2069)

Visual FoxPro does not support the DataEnvironmentDEClass and DEClassLibrary properties for form sets. An error occurs under the following conditions at design time:

• When attempting to convert a form to a form set after the DEClass and DEClassLibrary properties have been specified for the form.
• When attempting to add a Form class that specifies the DEClass and DEClassLibrary properties to a FormSet class when the form set is open in the Form Designer.