I am attempting to use the Nightblade’s Amarasta’s Blade Burst skill. I added some skill points to it, though when I assign the skill to the RMB it does not work. I am using a melee weapon. The skill numbers for Amarasta’s Blade Burst are highlighted in blue on the skill tree. Does that have something to do with it? What do the blue numbers mean? Thanks!
Blue numbers mean you have +skills.
Ah, that makes sense. Blue numbers denote skills that have points in them but are yet to have the maximum points applied. I’m still stumped as to why the skill does not work. I played a different class of character a good part through the game before the final release and never encountered this problem.
Keep in mind that with +skills, you can go up to 10 points past the ordinary maximum of the skill, so you can still max it out.
Huh. Then this must not be a +skill as only 4 of 16 possible points are currently given. It is 4/16, highlighted in blue, and does not work.
Maybe you have a devotion skill attached to it that you can’t use?
What are you using in your offhand weapon slot? I just did some testing and it worked for me for dual-wield, sword and board (shield), and two hander when assigned to RMB. The only thing I can’t test atm is a caster offhand like a book or effigy.
Axes in each hand. Skill requires melee or two-handed ranged weapon. I’ve tried several weapon combinations to no avail.
SOLVED: I removed the “Ring of Readiness” and the blue numbers turned white and the skill started working. Might be a bug.
Can you describe what happens when you trigger the skill?
I have the exact same problem. I added the skill to 1,2 and rmb (to test) and when I use any of thosde it just does a basic attack.
If I equip a gun, the skill greys out, so something is working right.
I also tried removing all my other items, leaving only a 1H sword, and nothing.
It is greyed out because you need a 2H ranged weapon.
Like I said; something IS working right 
But I figured it out. It only actually fires when targeting an enemy, specifically.
Guess Diablo got me used to spells just firing indiscriminately.