I was afflicted with Grey Rot in T3 Lower raidfinder today. While it ticked away, I lost the ability to use my assassin soul shard abilities. I thought it was a hotbar bug, and replaced all the icons with new ones from the abilities menu, but the problem persisted. I was forced to use normal combos until the Grey Rot debuff expired, at which point all my abilities were restored.
Thats exactly what grey rot does.
not a bug, as Frenjoerd already wrote. that’s part of the debuff 's annoyances, also soldiers will not be able to irritate, etc