Anyway, I rewrote it like this, to try to indiscriminately convert every frame of every layer of the timeline: var timeline = fl.getDocumentDOM().getTimeline();for(var i = 0; i < timeline.layerCount; ++i) { timeline.setSelectedLayers(i); timeline.convertToKeyframes(0, timeline.frameCount);} That seems to work on everything except layers where motion tweens have been used.