Cant equip a Helmet

So my problem is that i want to equip sometimes a different Helmet (Poachers Greed) But for any reasons i cant equip it...

This is my actual Build:
Unravel
Novocaine
Omniverse
Skidbladnir
Warp

Lumino Blossom
Creed Catalyst
Prowess
Diamond Fusion Neckle

I want to equip the Greed Helmet for the Loot Bonus but the Game doesnt allow me to wear it. Is there any restricion? Well i figured out when i uneqip Prowess i can equip the Helmet... Why is this?

 

If you take off unravel you no longer have enough agi for your other gear no? And poacher's greed also puts you below the intelligence req for diamond fusion necklace. If you want to use poacher's greed you'll need to use a different build.
It seems strange that you'd be able to use poacher's greed after unequipping prowess. Does it work even after /class-ing and joining again?