I tried doing main questline today. During that time, there were several times, when my character ended up falling through the floor or walls. First time, dwarwen automaton kicked me through the stairs, and I had to run back to him again. Next two times happened in Nighthollow keep, one time while using void portal, I got teleported right back to the entrance, next time void mob kicked me through the floor again, and again I ended up near the entrance. Fight with Lady Belain was the epitome of frustration. First shademother sent me flying under grid, endlessly flying down. Notification on the screen told me, that /stuck command will not work, and it did not work. I managed to teleport to wayshrine, came back, tried again. This time, third shademother sent me flying down again. I could not even use teleport to wayshrine at first. After some tries, I teleported sucessfully. Third time was the same. I could not even chip 1% out of boss health, without falling through the floor and having to run back from wayshrine again. after that, game kicked me out to the main screen.