The error is harmless to your save if corrected properly. It doesn’t mean your save is lost—just that one or more cars have a corrupted or manually tampered heat level. A quick hex edit or a modern save editor will restore full functionality without losing progress, cars, or career stats.
Here is the definitive troubleshooting guide. Follow these steps in order.
), the heat value might be stored in a way the editor no longer recognizes. Checksum Mismatch