Progress.Lang.ProError is the super class for all ABL built-in and user-defined classes that represent errors in the ABL structured error handling model. You cannot directly inherit from this class. Instead, the immediate subclasses of this class represent the two major types of classes in ABL:
Progress.Lang.ProError inherits from Progress.Lang.Object and therefore inherits all the common methods and properties needed for managing user-defined objects in ABL. It also implements the Progress.Lang.Error interface which provides all the properties and methods relevant for an error object.
Specifically, this class provides the functionality to retrieve error messages, error numbers, and the contents of the error call stack.