Almost every "Hall of Fame" mod—such as Europa Barbarorum , Roma Surrectum II , and Lord of the Rings: Total War —was built specifically for v1.5 or v1.6. If you aren't on these versions, the best community content simply won't run.
Are you having running it on a modern OS (Windows 10/11)? Download Rome Total War Collection v1.51 / 1.61...
Analysis: Rome: Total War Collection (v1.51 / 1.6) The represents the definitive "Gold" state of the original Rome: Total War . While the base game launched as a revolution in the strategy genre, these specific versions are the bedrock upon which the game’s legendary longevity and massive modding community were built. The Technical "Sweet Spot" Almost every "Hall of Fame" mod—such as Europa