This may or may not be a bug, but in my current game I noticed that over the last 20 turns my relations with all the AIs, including my allies, degraded significantly without an obvious reason (to me anyway). Where I had treaties, most them have cancelled at least some of them. What's more, one AI even turned sour after I lent them my troops for their fight against a third party. Twice. First it impose the trespass embassy action, and the second time its attitude switched to hate-filled, along with further cancellation of treaties.

Does anyone have an idea what's going on? Is it because I am doing too well and they feel threatened? Sure, at least one AI has the modifier "they see you as their closest competitor". But that doesn't look so prominent to outweigh all other factors. And I don't think that applied to my allies.

I don't feel like I have really done anything that unusual. I started some skirmishes against one AI and am preparing for war, but haven't declared it yet. I just advanced an era, way ahead of everyone else. That's probably about it.

Is there something I'm missing? I attached the latest save game, if of interest.

Poles Turn 116.ctr