Convalescenes doesnt work

I already tried everything to fix that, but it still wont work. Yesterday it was working fine and today i cant use is. I already tried switching gems, trying a lesser Level gem, checking my Equipment, checking if i have enough inteligence to use it, having enough spirit, starting the game new. Nothing works. Can someone help me? It really sucks that i cant let my energie shild recharge if you only have like 700 HP.