In a large modpack, mods drift apart. Mod A calls a method in mod B; B changes that method in an update; A - frozen at its own release - throws NoSuchMethodError. These breaks are usually latent: nothing at startup, nothing on world load. The game only crashes when that exact code path runs, sometimes hours into a playthrough.
Until now the only fix was holding a mod back. LRM Fixes patches the call sites instead, so you can keep updating.
Each patch is an independent mixin that redirects a broken call to whatever the target mod actually provides now.
Targets are resolved by name and parameter count, never by exact signature - because the signature is what broke in the first place. Resolution happens once and is cached. A patch therefore survives the next upstream change too, in either direction, instead of breaking a second time.
The redirects are safe by construction: they carry out the call that was always meant to happen. They prevent a crash and change nothing else.
defaultRequire: 0. If a target mod is absent, or upstream finally repairs the break, the patch is simply skipped. It can never be the reason your game won't start.The list of patches changes from release to release. See the changelog of the file you downloaded: it names each patch, the two mods involved, and the symptom it prevents.
Used in the Legends Reborn: Medieval modpack.
