The description for War Hero needs this info, because without it, it is missable:
"If Season Unending has been completed before starting this quest, then this quest is skipped and you proceed to False Front."
Basically, if Season Unending is completed prior to Compelling Tribute, the quest is skipped.
Source - Stormcloaks
Source - Imperials
Fun Fact: In old Nordic slang, to "take an arrow to the knee" meant someone got married and in fact has nothing to do with being physically shot in the knee with an arrow.
Currently in the Borderlands, breaking the backs of mules.