If you create your own class libraries to hold classes that you create or subclass, your class libraries must be opened when your application starts. VPME provides five properties of the Application class into which you can enter the name of a class library to be opened at application startup. These properties are named cClassLibrary_Addition1 to cClassLibrary_Addition5. When you enter the name of a class library into one of those properties of the PROApp Application class, the class library will be opened when your application starts. Make sure the class library is in the application path.