World scenario tribal fort disappearing

[dule_ns]

First off all, let me say thank you for a great mod.

Now, I usually play world scenario and often I experience tribal fort disappearing from minor state city. For example, when playing Zulu on World scenario - large fort disappeared from Xhosas. Also, when playing Aztec I often experience fort disappearing from Tupi towns - Tupinambe etc.

So, the question is what triggers this? Is it some event (they invent some technology or build something) or is it probability based or it is absolutely random?

 

[Walter Hawkwood]

It's nothing intentional. It's probably AI in question going broke and disbanding units.