Understand what DHMPEMFixer actually fixes

The core conflict

Distant Horizons and MPEM both modify Forge's proxy classes—the internal systems that handle client and server communication. Without a fix, these modifications conflict:

• Client side: MPEM removes or changes fields in the Forge client proxy that Distant Horizons expects to find, causing a null pointer crash on startup
• Server side: Similar field conflicts occur in the server proxy, breaking multiplayer setups

How the fixer works

DHMPEMFixer uses mixin code to inject patches into the proxy classes *after* both mods have loaded. It restores or preserves the fields that each mod needs, preventing them from being completely removed or left empty.

This happens automatically during mod initialization—you don't configure anything.

Why you need it

Without DHMPEMFixer, you cannot run both mods together on Forge. The crash is unavoidable. With the fixer installed on both client and server, both mods coexist peacefully and function as intended.