Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

You are attempting to run the program after you have
unloaded the main module. Every program must have a main
module so QBX knows where to start running the program.
Either:
   ■ Use the Load File command from the File menu to reload
     the main module you unloaded.
   ■ Use the Set Main Module command from the Run menu to
     make a currently loaded module the main module.