_getOffset2DMatrix = function(e, offsetOrigin, parentOffsetOrigin, zeroOrigin, isBase) {
if (e === window || !e || !e.style || !e.parentNode) {
return [1,0,0,1,0,0];
}
var cache = e._dCache || _cache(e),
parent = e.parentNode,
parentCache = parent._dCache || _cache(parent),
_cache = function(e) {
if (Draggable.cacheSVGData !== false && e._dCache && e._dCache.lastUpdate === TweenLite.ticker.frame) {
return e._dCache;
}
var cache = e._dCache = e._dCache || {},
cs = _getComputedStyle(e),
as we can see, function "_getOffset2DMatrix" has check for "!e.style" but into function "_cache" we send "e.parentNode". "_cache" function has no checks
and try to get computed style. in this case
e.nodeName === 'HTML' && e.style && !e.parentNode.style
// e.parentNode is frame.contentWindow.document