Visual Class Library _BASE and others are in Home(1) + 'ffc\';
you need to add them to your project:

drag and drop from windows explorer
or
click the add... button on project manager


>Hi,
>
>When I build the app. VFP9 prompt out the following error.
>
>Visual Class Library c:\program files\microsoft visual foxpro 9\wizards\_framewk.vcx has the following errors:
> Visual Class Library _BASE - Undefined
> Visual Class Library _UI - Undefined
> Visual Class Library _APP - Undefined
> Visual Class Library _TABLE - Undefined
>
>Why ?
>
>Please advise.
>Thanks.