If you have a Stand-alone Application and want to include data before the application was built, you will need three files.
A double-clickable application requires the data file (.4DD), the data resource file (.4DR), and the log file (.4DL). These files are located in your original database folder, next to your structure file (.4DB).
If the .4DR file is missing, the alert, "A Log File is mandatory to use this database" appears.
If you are missing the .4DL file, you will receive an alert with, "The correct Log File for this data file could not be found. Try to find it. If you cannot find the Log File, make a full backup of the data before creating a Log File."