Install the Fallen Empires mod from the Steam Workshop or Paradox Mods
Enable the mod in the CK3 launcher
Make sure the mod version matches your CK3 game version
Place the mod above incompatible mods in the load order
Disable other total conversion or map mods if the mod will not load
Verify the mod files are fully downloaded and not corrupted
Clear the CK3 cache if the mod does not appear in game
Start a new save after enabling the mod
Check the mod page for required DLC or dependency mods
Update or roll back CK3 to the version supported by the mod
Remove conflicting submods, UI mods, and overhaul mods
Confirm the mod is installed in the correct Documents/Paradox Interactive/Crusader Kings III/mod folder
Subscribe again if the mod is missing from the launcher
Launch the game once with only the mod enabled to test it
Read the mod description for special installation steps
Use the correct checksum or beta branch if the mod requires it