If you encounter the mentioned error, it can mean that your database is corrupted. To fix it, you need to go to the location where the program is installed. The default folder is C:\Program Files\Guard1 Plus or C:\TimeKeeping Systems\Guard1 Plus for Windows Vista and Windows 7. From there, right click on the G1Master.g1p file, select cut and paste it to your desktop. After you did this try opening the program again. If the error isn't encountered anymore, your database is corrupted and you will need to perform a restore of you files. You can find more information about this matter, on the following website. If the error appears, contact the developer on the official website.