This is my leafletjs iframe in a wordpress blog: http://www.kemeling-consulting.com/cresh-map-viewer/
The iframe is working fine in firefox and chrome, in IE11 the popups are not working. They are getfeatureinfo requests from the geoserver WMS.
The website also works fine (popups work ok) in IE11 directly: http://126.96.36.199:8080/cresh_map/mapla.html
I added this in the header.php file
Does anybody know what else I can try?