For anyone having the same problem:Import SAP's bootstrap for the sap-ui-core, on the application were you are setting up the iframe
<script id="sap-ui-bootstrap"
src="https://sapui5.hana.ondemand.com/1.48.17/resources/sap-ui-cachebuster/sap-ui-cor...
Unfortunately i'm having exactly the same problem. When embedding the frame in a SAPUI5 application everything goes well, the "parentOrigin" is passed, but if called from other source the parentOrigin is empty.Any tips?