Can anyone explain why I can't put this piece of armour on?

I just got a new piece of armour, and I seem to have enough stats to put it on but when I try to, it doesn't work. This issue still persists even after restarting the game and using /class. How do I fix this?

 

See if it has any negative Skillpoint bonuses. You can't equip a piece if another is dependant on a certain number of SP

 

Also check if you weapon's own skill points are adding to your sp total.

Is it by chance the Berserker's Helm?