Object Type in the To Do List: Profile part.
Meaning: The profile has a split knuckle but was not split using this knuckle. In most cases, this knuckle is inherited from the split knuckle on a parent plate. Alternatively, the knuckle might depend on the parent plate geometry.
Split the profile using the knuckle point.
If not required, change the knuckle to a bend, or ignore the knuckle.