Diagnosis
You have specified an ABAP application class to be generated. Thespecified class &V1& is currently a subclass of standardclass CL_UPWB_BSP_APPL. Such classes are used to modify thestandard behavior of the application. The classes are not generated butare created by the Designer so that modifications are not lost everytime a generation is executed.

System Response
If you regenerate the class, the current class &V1& will beoverwritten. It will no longer be a subclass of standard classCL_UPWB_BSP_APPL. It will also be necessary to regenerate theclass in the Web Interface Builder each time the application is changed.
The advantage of the generated class is that it facilitates complexmodifications.

Procedure
Generate the class only if the subclass does not meet your modificationrequirements sufficiently. SAP recommends that you retain the old classas back up, using another class name.
You will find more information in the F1 documentation on the "Generateclass" setting.