I am having this issue also, which I actually realized about 10 minutes ago. 3 of my Sims had to give presentations. They each had a presentation board in their inventory, and I had 2 of them take the boards out of their inventories to work on them. I was able to perform all normal actions regarding the board (refine & organize, practice presenting, receive feedback, etc). 1 Sim completed his presentation board, so I put that back into his inventory. The other Sim left his out in the hallway so he could finish later. The next Sim day (not sure when exactly) I went to have my Sim work on his board that was in the hallway, and it was gone. I remembered this bug so I checked the other Sim's inventory, and his board was gone too. Oddly the Sim who didn't work on his board at all also had it disappear from his inventory. They must have all disappeared at the same time. I honestly did not even notice the board disappear from the hallway. It was really weird, I just went to click on it and it was gone. I am really hoping that if I have them do all their homework and study super hard for their classes that require a presentation then they won't fail, but....wishful thinking maybe.
