What do you make of this error message?

[BladeOfSharpness]

Could not resolve reference to object with loadID Thing_MedTimes_Boots_Plated1133663 of type RimWorld.Apparel. Was it compressed away, destroyed, had no ID number, or not saved/loaded right? curParent=ChangeDresser.ApparelColorTracker+ApparelColor curPathRelToParent=

Would you say it relates to Medieval Times, or to Change Dresser?
I have a change mirror in game, but no dresser also.
And this is not upon load, but after one hour playing the game (current session, overall the game ran fine with the same mods for like 50+ hours).

Probably a ninja update from a mod screwed the game? But I'm confused, which one.