This is Part 3 of 3. After reinstalling MMI (Part 2), restore the charts you backed up in Part 1.
Close MMI if it's open.
Make sure hidden files are visible — open any folder, go to the View tab, and tick "Hidden items."
Copy your backed-up Charts.s3db back into C:\ProgramData\Jovian Archive Corp\Maia Mechanics Imaging\Data, replacing the new empty file there.
Open MMI — your charts should be back.