I think your problem is that you put gravity as negative. Define it as a positive number, then switch the direction of the arrow.
Unchecking the simulation in the add-ons and rechecking it along with closing and re-opening the file seemed to make it work.
direction of the gravity force should not matter. I've had that going in other directions before.
seen it pop up in a few spots like bolt connector material but not specific to 2014 and never seen i there