The fetch feature was originally created for larger agencies and schools with multiple licenses. The fetch feature will only work on computers that have previously activated a license(s).
Fetch is great if you need to re-install your computer/Adobe InDesign/Grid Calculator Pro Edition then you can, the second time, use the fetch feature instead of contacting support or manually search for your license(s).
All you need to do the second time is to enter your registered email address for that specific computer and then press Fetch. The activator application will then fetch your license(s) registered to that computer.
Please note that for certain cases/computers the fetch feature might not work. In most cases it will work fine. If you encounter any problems please contact technical support.