For future reference and anyone having the issue that
@two2wheels had:
The calculator "remembers" the last file that it had opened and when it is launched, it is automatically opened. There has been an occasional issue where the calculator forgets the last file and doesn't automatically open it when the calculator is launched. When this happens the first reaction is thinking that all of your recipes and ingredients are lost which is not the case. I haven't been able to determine why the calculator is forgetting the last file that was opened, it has only happened to a few users and I don't know the trigger.
The fix for this is easy. You just need to do a "File->Open" and open the juice file that you have been working with. The problem for many users is they don't know the name/location of the file in order to open it. In case this happens to you, make a note of the name of your file, shown in the title bar of the calculator, and also make note of the directory that you have the file saved in. By default it is in a subdirectory of your "My Documents" folder with a subdirectory name of "JuiceCalculator" or "EJuiceCalculator".
Also I would highly recommend that you tell the calculator to automatically make backups of your juice file. You can turn this on by going to "Tools->Options" and go to the "Backups" tab.