Guild Wars 2

When dual wielding and having one weapon enchanted with Sigil of Purity (60% Chance on Critical: Remove a Condition (Cooldown: 10 Seconds)) and other one enchanted with Sigil of Earth (+60% chance to do 5s bleed on critical), Sigil of Earth becomes bugged and doesn’t work.
It may happen to some other combinations of sigils, but this is the only one I know of.

edit: I think all chance to proc on crit sigils with cooldown bug the sigils which have chance to proc on crit but without cooldown