The Gettier Problem Explained and Debunked

Edmund Gettier famously raised an objection to Justified True Belief theory of knowledge by proposing cases of justified true belief, Gettier cases, that are intuitively not knowledge.
I think these cases are not JTB. I've said that before. But I think the reason Gettier Cases are not JTb has to do with problems in epistemic logic.