1. Have enough fury cost reduction for Weapon Throw to reach theoretical 0 cost
2. Ability (e.g. Weapon Throw) is set at primary skill (mouse skill)
3. You have 0 fury (e.g. before starting a battle)
Attempting to activate ability by clicking on a target causes character to not move at all and only generates a "not enough resource" error.
According to a previous thread on Weapon Throw, a different" 0 fury cost bug" was addressed which may have caused this regression. http://us.battle.net/d3/en/forum/topic/6412413451?page=3#41
Character should move to the target to attempt melee when at 0 fury.
If you don't satisfy requirement #1 (remove one of the items offering fury reduction), the Barbarian will attempt melee when not enough fury (even when at 0 fury).