How to Install Puzzles Lib Correctly So Your Other Mods Stop Crashing

Most players do not go looking for Puzzles Lib on purpose. They go looking because a mod they actually want refuses to start without it. Getting the library right is mostly about matching it to the loader and game version your other mods use.

Match the Loader First

Puzzles Lib ships separately for Forge and Fabric. Putting the Forge build into a Fabric profile, or the reverse, will not work even if the file name looks similar. Check which loader your modpack or profile uses, then grab the Puzzles Lib build for that same loader. If you run a loader that has its own ecosystem, follow whatever build that loader's version of the library provides.

Match the Game Version

A library built for one major game version generally will not run on another. If your dependent mod targets a specific game version, use the Puzzles Lib build for that same version. Mixing a newer library with an older dependent mod, or the reverse, is a common cause of startup crashes and missing-class errors.

Place It Alongside, Not Instead Of

Drop the Puzzles Lib file into the same mods folder as the mods that need it. Do not remove it once those mods are installed, and do not expect it to replace them. It is a supporting file. When everything matches, the dependent mods load and Puzzles Lib stays invisible, which is exactly the intended result.