Diplomacy fail - after circa 4000 turns most relations reset to 0.

[Tosterus 0]

Hi there,

After around 4000 turns my country was kicked out of alliance (there was no pop up that it happened - I've just noticed that my former allies have standard country colors in diplomacy screen). Most of the countries around the world have 0 points attitude towards my country. Nevermind if I insult them or try to increase relations. 

Any guesses how I can fix that?