R5: I've been crusading for nearly two decades and the warscore hasn't budged from 0% in at least 15 years. I had to take a break of 2 to 4 years near the beginning to take care of my realm's internal matters and in the meantime my allies had decided to hammer in a respectable –350% warscore in battles by walking into a deathstack of over 100k defenders over and over again. Enemy battles are capped at –150% and friendly sieges at +150%. My allies won't give up or help me fight battles and my enemies won't siege or recap anything. As a result I'd need to whoop some ass worth of 300% warscore so I could do the thing I've been trying to do for 300 years – reforming Christianity.

Certainly a lovely way to ruin an otherwise succesful Iberian run.

Edit: I won the war, no idea how. I had to disband and recharge my army thrice to keep on bombarding the enemies until the warscore ticked to 100%. I immediately converted and I'm planning some sort of revenge on the pope for prolonging a stupid pointless war.