While playing Act 3, I was in Caverns of Frost Level 1. My inventory had just hit max capacity, so I used a town portal. In the middle of the cast, I got the error that My game session had been terminated. upon re-entering the game, I had lost everything in my inventory, except equipped items.
Overall, nothing lost except a little bit of progress and potential gold/salvage material, I just wanted to bring it up.
Thanks for your time.