Who's taking my money?!

I think I'm pretty sure now that a broken vassalage caused the discrepancy I'm experiencing.

I have a habit to save a game every few days with a different name, that way I have about 20 savefiles from my current campaign. I've checked them all, and I find that the predicted treasury was very much accurate, up to +-10% (that's normal, of course, anything can happen between two turns).

Those 11000 FL I mention earlier was a tribute from my vassal Denmark. When they broke the alliance with me, the income obviously stopped, but the Financial report was still showing it.

I also had a vassal before (France), but when the alliance was broken (actually I attacked them), there was no discrepancy.

Therefore, my conclusion is that the breaking of a vassalage can sometimes trigger a corrupted Financial overview. Maybe someone who is in a similar situation can confirm this (or prove that I'm wrong)

BTW, alpaca, you're right, there was a starting treasury in RTW.