Installed fifteen mods and now the flags are black, focuses do nothing, and the game dies on the loading screen? Nine times out of ten the problem is not the mod itself but its place in the load order. Hearts of Iron IV loads mods strictly top to bottom from the launcher list, and when two files collide, the one lower in the list wins. Here is how load order works, where to put patches, and how to build a compatible collection on the first try.
How HOI4 loads mods
The game reads mods from the launcher list top to bottom, file by file. If two mods contain the same file — both edit German history or the same infantry icon, for example — only the version from the mod lower in the list survives. That is why load order is a mechanic, not a suggestion: a misplaced patch stops working, and a mod accidentally moved above the mod it edits breaks it. The game version does not matter: the rule is identical for 1.19x and older patches.
Basic rules of load order
- 1Put patches and submods below the mod they extend: their files must override the original.
- 2Do not mix major total conversions (Kaiserreich, Millennium Dawn, Old World Blues) — they are two incompatible worlds.
- 3Utilities like Player-Led Peace Conferences are compatible with almost everything — keep them near the bottom of the list.
- 4Never duplicate mods: a Steam subscription plus a manual copy in the mod folder is a reliable way to get doubled events.
- 5Restart the launcher after every reshuffle — the game reads the list only at startup.
Typical setups
Kaiserreich and its submods: the main mod on top, graphics add-ons and translations below it, small patches at the very bottom. Millennium Dawn: the conversion on top, the optimizer and localizations below, and not a single other total conversion in the list. The Road to 56 and Expert AI get along: conversion above, AI improvement below, so it correctly overrides the balance edits. BlackICE is a self-sufficient heavy mod: the fewer neighbors, the more stable it runs.
How to check the order is right
- 1The launcher shows no red exclamation marks next to mods.
- 2The game reaches the main menu without crashes and the checksum has changed — mods are actually loaded.
- 3Quick test: start a throwaway campaign as a minor country and run a couple of in-game years at speed 5.
- 4Focuses, events and icons look the way the mod pages describe them.
In multiplayer the order matters twice as much: every player needs not only the same collection but the same sequence — otherwise checksums will not match and the server will refuse the connection.
Kaiserreich
Welcome to the world of Kaiserreich! As 1936 dawns, the Weltkrieg's legacy lies heavy upon the shoulders of a new generation.
Millennium Dawn: A Modern Day Mod
Millennium Dawn moves Hearts of Iron IV into the twenty-first century: the campaign starts in the year 2000 and runs into the modern day, with globalization, rising extremism and emerging world powers replacing the Second World War setting.
The Road to 56
by Greatexperiment, The Brit +4
The classic HOI4 overhaul: timeline extended to 1956, a massively expanded tech tree and alternate-history paths for nearly every country.
If a conflict still appears
Narrow it down: disable everything, then enable mods in batches of five until the game breaks. Once you find the pair, decide which one matters more and drop it lower so its files override the rival. If both are essential, look for a compatibility patch in the Workshop: for popular combinations the community has long since made one. Full diagnostics with logs are covered in our errors and crashes guide.
The collection is set up — the rest is practice. For installing mods without Steam, read our installation guide; for what to pick in a new campaign, see the best HOI4 mods roundup; and the full catalog with filters lives on the HOI4 page. Good hunting! You can skip the manual sorting: Irony Mod Manager imports a Prime Mods build as a single file with the order already saved.