Unable to activate plague nova skill

I believe if the player takes certain actions it is possible to lock yourself out of using the active of the plague bearer skill


I've set plague bearer to be activated and set plague burst to my ability key but even when I'm stacked to 100% I cant activate the ability


I'm not sure how to recreate this but I might have unchecked both of the weapon slot boxes in the skill panel at one point and I think it disappeared, has anyone else run into this?

I have just run into this now. Some how locked myself out of being able to use the ability. I meet all the requirements and it also lets me store up the poison. But when you hover over the skill on your bar it states Skill Cant Be Used. Unsure on what to do here.

dont know why my images didnt work so here you go for clarity

https://imgbb.com/tm05pZ2
https://imgbb.com/K0HygPN

Not sure if you figured this out by now but, just in case, I had also run into this issue and it was because I accidentally slotted plague burst into my hotbar instead of plague nova. Hopefully that helps!