I drag it on to any neuron button and even bind /cast Sunfire or /cast Sunfire()

It appears on the action bar but is not clickable or able to be pressed by it's corresponding keybind, i've tried placing it in slots that spells definitely work on... the spell does not activate what so ever.

no movement on this from the original post. closing

after dropping a spell on the action bar, try reloading (/reload). this usually works for me.

I'll login today and give this a shot, although i'm pretty sure i logged and tried it.

odd, I use sunfire on my druid all the time. Is it specifically Sunfire, or any spell you drag?