Package has unversioned properties but mapping file is missing, can't serialize

[4sval]

Packages with unversioned properties are expected for UE5+ games, but there are solutions to keep reading them with FModel.
Using one of the dumpers below, you can generate a mapping file containing a schema of your game's classes, structs, and enums. This schema is subject to change after every new update, so, should be regenerated after each one in order to avoid errors.

Dumpers you can use:

• https://github.com/Encryqed/Dumper-7
• https://github.com/UE4SS-RE/RE-UE4SS
• https://github.com/OutTheShade/UnrealMappingsDumper

Read their READMEs for more information on how to use them.

Once the mapping file is generated, open your FModel settings and set a local mapping file like so.

---

If this is too much for you, you can use another game's mapping file generated on the same UE version your game uses. It won't contain the customs classes, structs, and enums your game has, so expect various errors.