javascript - Why does OneDrive js picker sometimes have null opener -

i trying integrate onedrive picker our web application , after reading nick's answer question on 10/02/2015 have chosen route of using iframe , utilizing postmessage. after inserting iframe button open onedrive picker , selecting file, popup window persists spinner icon , there error in console r null. know that, given this question having form can cause issue , removed form in page loaded in iframe still see error window.opener == null (see screenshot below). has else seen before? had theory query parameters in url cause removing didn't appear resolve issue.

debugging onedrive.js when error occurs (and popup window persists after selecting file):

thanks!

so cause iframe being loaded in "popover" - div absolute positioning appears when link clicked , disappears after interaction over. , when containing div hidden, causing iframe reload - should try technique descibed here