Link to Reiksmarshal's unofficial bug reporting thread.
Some bugs:
Campaign Map
-CTD when merging units together after battle
-deadly slow scrolling on the map
-flickering and pop ups on the campaign map
-CTDs after finishing the round
-huge frame drops on the map, but battles and stuff run smoothly
-trade ship issues, couldnt make a traderoute
-faction ship flags flash between own flag and pirate flag
-"out of memory CTD" in grand campaign
-CTDs when you try to start a new campaign while you have another campaign going
Battle Map
-iroquoi soldiers cause huge framedrops
-"slowmotion" units in the battle of Quebec (RtI Campaign)
-missing sounds of gunfire, infantry, etc.
-cav gets stuck on gates/walls
-missing textures
-cav glitch, when they are attacking, they getting stuck
-you can hear "hidden" units marching
-sliding soldiers
-advisor screen pops up, but it takes few seconds until he says something
-in some battles the water is black
-"black-stair-shadows" on horses when you turn shadows on
AI
-pathfinding
-ai attacks frontal infantryline with cav
-ai cav running into spears like there is no tomorrow
-ai dont use all units sometimes
Overall
-loading times for some user
-floating flags bug
-settings are set back after CTD/Battle
-text bug, couldnt read text because its to small