I just got prog-blocked on the ship at the prologue by picking up two water barrels I was going to use to douse some flames. I dropped one close to me and then my character was unable to take any further action. I cannot drop anything to get under weight limit as it just throws a "Can't move; Encumbered" warning. I have to reload the game as I am stuck.
To Repro:
1) Be just under your capacity limit for weight but close to the limit.
2) Somehow put two barrels (haven't tried with crates or anything bigger) next to each other on the ground nearby.
3) Pick them both up quickly. They weigh about maybe 60 stone, so make sure that dropping one of these barrels still won't take you under the weight limit.
4) Drop one of the barrels as close to your character as you can. You should still be over-encumbered.
5) Try to drop the other barrel, or anything else to lessen your encumbrance.
6) Notice you cannot do anything anymore. Your character will always warn you of being over-encumbered with any action or button-press. NOTE: This does NOT happen if you drop the first barrel very far away from your character. Could be a line-of-sight issue?
It's oddly specific for a bug. But there are two water barrels next to each other on the deck of the ship in the prologue. That's the easiest place to repro this. I picked up a bunch of crap below deck before the incident happened.