A unique feature of 4D Compiler is that the error file can be used to debug a database interactively. When you compile your database, you have the option of saving an error file. When the Compiler options window appears, click on the Error File button and it gives a default name and save location to the error file. The default name is the same as the database being compiled and the default save location is the folder in which the database to be compiled is located.

Once the error file is created, quit compiler and open the database in 4th Dimension. Both the error file and the uncompiled database will be opened simultaneously in 4D. In the design environment under Use on the main menu, two new options have been added; next compiler error and Stop browsing error file. The 4th Dimension menu command, Next Compiler Error under Use, automatically finds and highlights the next compiler error and displays the error message or warning and the Stop browsing error will exit the interactive debugging mode. To launch the interactive debugging again, the designer must exit the database and open it once more in 4D.