This is one of those rare errors that happen once and tend not to reoccur. Please restart CostGuard and you should be fine.
If the error persists, download the newest version of the software by following these directions:
1. Exit CostGuard before doing the next step
2. Download and SAVE https://dl.dropboxusercontent.com/u/42405781/costguard.exe
3. Save to your desktop
4. Right click on the saved CostGuard.exe file, and click “Copy”
5. Explore to c:\Program Files (x86)\CostGuard.
Right click on the CostGuard folder (do not open the folder) and click “Paste”. Allow the old file to be replaced when prompted.
6. Open CostGuard to use the new version