So we have just started experiencing problems with web apps through Portal for ArcGIS 10.5.1 where the header controller widget is failing to load. The error I am seeing is:
create [themes/FoldableTheme/widgets/HeaderController/Widget] error:Error: Access is denied.
at postCreate (https://xxx/themes/FoldableTheme/widgets/HeaderController/Widget.js?wab_dv=2.1:84:11)
This is only happening on IE, on Firefox it works fine. Has anyone else experienced this problem? I've also noticed that this problem is possibly related to a specific build of IE (11.0.9600.19266), we have tried on a couple of other versions of IE (notably 1.0.9600.19236) and this problem does not occur.
Indeed and I would if I could but unfortunately Chrome is not permitted where we are, and although Firefox is available, IT have done something to it to make it unworkable!
Sort of thankfully I think I've tracked down the source of the problem (or rather a colleague of mine did), it seems that it's a known issue as per this page:
Hopefully this might help others who come across this problem...