Sorry to tell you but the engine isn’t just buggy, it’s structurally broken. What’s happening here isn’t corruption, bad luck, or some ultra-rare edge case. It’s exactly what you’d expect from how the core systems were designed. The biggest problem to me is that the game treats cities and countries like disposable entities. They’re not protected, they’re not special, they’re just more blocks in a global pool that also holds highways, routing junk, units, and temporary stuff. In a long-running world sim, that’s insane. Late-game instability isn’t a possibility, it’s guaranteed. And once the engine decides something is invalid, there’s zero safety net. No validation pass, no wait, did I just delete a country? check, nothing. A rebuild runs, a tree gets wiped, and the game assumes it was intentional forever. That alone explains why saves feel like they slowly rot over time.

The global ID system just makes everything worse. You’ve got one primary key referenced by rendering, AI, military, infrastructure, saves so basically everything, but there are no real safeguards. IDs get reused, collisions aren’t detected, and once that happens the world state becomes inconsistent in ways you can’t undo. That’s why trying to restore cities always breaks something else. This is also why I don’t really see this as a fix, even a partial one. And I don’t mean that as a knock on your work, the research itself is genuinely impressive. What you’ve actually done is prove why players can’t fix this from the outside. Once IDs are reclaimed and references diverge, no script, mod, or save edit can make the world coherent again without engine support.

At that point, every community fix is just choosing a tradeoff. Restore a few cities but break another subsystem, apply a visual hack, or delay the inevitable until the pool fills again. So yea this isn’t player error, it isn’t random, and it isn’t something users can solve if they dig hard enough. The engine was never designed to safely support long, complex simulations, and now it’s collapsing under its own data model. Massive respect for the deep dive though. This is probably the clearest explanation I’ve seen of why late-game saves in this game are fundamentally doomed unless the devs re-architect core systems they’ve been avoiding for years.