If you are using Internet Explorer 8 or earlier, depending on your browsers security settings, you may have trouble saving your Visual Economic Tool file. Users with high security settings will sometimes see a IE security warning after the click File>Save. After the error shows up, the browser refreshes the page and you lose entered information.
If you are having trouble saving your Economic File, you can either disable protected mode or add Visual-3D to your trusted sites. Updating to IE 9 will also fix this issue.