A: The previous user used too many cheats (specifically the "Pedestrians riot" or "Peds attack" code). The game flags the save. You need a "Cheat Remover" tool (available on GTASnP).
Analysis of Grand Theft Auto: San Andreas Version 1.01 Save Game Files SUBJECT: Technical Overview, Usage, and Compatibility Issues DATE: October 26, 2023 PREPARED BY: Technical Reporting AI gta san andreas v 1.01 save game