Hi DYWM. I have been practicing yoga for around 20years and have always found kneeling postures slightly uncomfortable so always use extra padding. More recently I have been finding lunge postures where the knee is down particularly uncomfortable especially if the aim of the posture is to drop the hips down and forward (hope you get what I mean as not sure how to describe it!) and often have to come out of the posture before the teacher says to do so. I wondered if there is anything I might be doing wrong in these postures, or anything I can do other than come out of the posture early. I almost feel like it is caused by too much pressure on my knee cap.
I am sorry to hear you have been in discomfort! Yes I know the movement you mean, dropped back knee lunge. If the discomfort is in the dropped knee then extra padding can be useful, if it is in the front knee then I would suggest not going in so deep and making sure your knee does not go past stacking over your ankle.