Are you researching the of how GMS2 bytecode is structured and reversed?
The following snippet is highly simplified and hypothetical. It illustrates a basic concept of how one might start to analyze a file: gamemaker studio 2 decompiler
Restoring source code after a hard drive failure or lost backup. The Complete Guide to GameMaker Studio 2 Decompilers:
Several decompilers and reverse engineering tools are available for GameMaker Studio 2, including: Developers : Use version control and backup systems
: For developers looking at legacy projects, this tool handles GameMaker 8 executables by extracting assets and code from the "gamedata" section. Interesting Perspectives & Blog Posts