I've had a series of odd bugs, or at least one serious bug and a few odd events.
I'm playing as the Old Swiss Confederacy. My towns cannot seem to generate trade at all, especially since all my generals get the "Incompetent Trader" trait no matter what I do. My mining town in the southeast (Suenders or something) has the option to build a very expensive copper mine, but it doesn't generate any income at all even though it says it should. I already have a gold smelting place there. But Bern is different. I built a Big Inland Port there and its trade went from 0 to a few hundred instantly. Cobbled roads did the same thing. After that, every building that increased trade increased it so much that I make hundreds more thalers a turn and increase population growth by up to 4% per building. Trade-increasing buildings anywhere else aren't worth it because they generate maybe 20 thalers if I'm lucky. I have no idea why.
Another turn, I noticed that a bunch of agents spawned around Bern and that nearby foreign city belonging to some yellow faction. I got four merchants, a diplomat, a spy, a priest, andan assassina cheesemaker, all of whom had 0 skill. The yellow faction got four merchants and a diplomat. I have no idea why.
The serious bug is a cursor issue, but not the usual one. I began a turn getting a message from the Merchant's Guild, which wanted me to buy out some nearish foreign merchant. I clicked on the magnifying glass button to show me where he was, and suddenly the cursor disappeared. It flickers on every few seconds, and still highlights whatever I mouse over, but I can't click on anything and have to quit by Ctrl+Alt+Del.