It depends on the system you use. For windows, you can still load your save on a new game installation. For Android, you update the gem to the next version.
Save file locations are found in the following directories.
Windows: %APPDATA%/RenPy/TownOfMagic
Example: C:\Users\[USER]\AppData\Roaming\RenPy\TownOfMagic
MacOS: library/RenPy/TownOfMagic/
Linux: ~/.renpy/TownOfMagic
Android: Phone\Android\data\www.townofmagic.com\files\saves
If a save loading does not work, try loading a save from the Q section of the loading screen.