Older 16-bit versions of Visual Basic controls with the file extension .vbx are incompatible with this version of Visual Basic. If you attempt to load an older project containing .vbx controls, Visual Basic will warn you that the controls are unavailable or incompatible. You have the option of continuing to load the project without the .vbx controls but, of course, the application will not function properly.
If you have older Visual Basic projects that contain third-party .vbx controls, contact the control's manufacturer to inquire about .ocx replacements.