The most important element of a Learning Organization is a Just Culture, because only in a Just Culture are people free to talk in detail about things that went wrong without fear for repercussions.
Do not confuse this with a No-blame Culture. People will still be held accountable in cases of gross neglicence or criminal acts. A lot of the Just Culture literature is about how to draw this line between gross negligence and other things that go wrong and about who gets to draw that line.
However, the crucial importance is that only in a Just Culture environment will it be possible to learn the real stories behind what went wrong. Without those stories, thus without a Just Culture, attempts to create a Learning Organization will fail.