What is a gamedata file?

A gamedata file is one of many files used by Fields of Mistria to store your save.

Where do I find my gamedata file?

Do Win+R, copy this, and hit enter: %USERPROFILE%/AppData/Local/FieldsOfMistria/saves. Look for the most recently updated .sav file, that's your most recent save. Copy it over to a safe location. Next, you want to download the most recent release from https://github.com/NPC-Studio/vaultc. Run the following command on your terminal or powershell: path/to/vaultc-x86_64-pc-windows-msvc-v0.1.0.exe unpack path/to/savefile.sav outputfilename. Inside the generated zip there are various .json files that include gamedata.json. This is the file you want to input here.