If you are looking for legitimate ways to mod or patch games built in GameMaker (rather than the engine itself), developers typically use: UndertaleModTool:
For users looking to set up legacy versions of the engine, this guide covers the installation of GameMaker Studio 1.4 in current environments: universal gamemaker patcher 2021
: It is used as a dependency in projects to modify or "patch" GameMaker runtime files, often to enable features in restricted versions or to fix legacy bugs. Version Focus If you are looking for legitimate ways to
UGMP 2021 is a reliable time capsule for legacy GameMaker versions. For modern GameMaker development, it's useless. If you still run GMS 2.3 from 2021 and accept the legal/security caveats, it works as advertised—smoothly, silently, and without bloat. it works as advertised—smoothly