The Source property specifies a string expression representing the object that generated the error; the expression is usually the object's class name or programmatic ID. Use Source to provide information when your code is unable to handle an error generated in an accessed object. For example, if you access Microsoft Excel and it generates a Division by zero
error, Microsoft Excel sets Err.Number to its error code for that error and sets Source to Excel.Application.
When generating an error from code, Source is your application’s programmatic ID.class, Source should contain a name having the form project.class. When an unexpected error occurs in your code, the Source property is automatically filled in. For errors in amodule, Source contains the project name.
Description Property | Err Object | GetObject Function | HelpContext Property | HelpContextID Property (VBA Add-In Object Model) | HelpFile Property | LastDLLError Property | Number Property | On Error StatementApplies To: Err Object | WebClassError Object