I've inherited an ArcGIS Portal site which was set up some time ago and in which people can successfully create maps and apps and link to them but there's a problem with using the save as option when trying to make a copy of an existing map. The saved copy is given an invalid URL which means it then can't be opened. It looks like this is probably a problem with the original configuration of the Portal. If I go to the ArcGIS Portal Directory page at ...myportal.../sharing/portals/self I can see that there is a property called portalHostname which looks like it has a typo in it which is what I'm seeing in the generated URLs. It shows up formatted like this: /\foo.com\bar\home. This should really be foo.com/bar as I can see it in a separate installation that works fine.
Does anybody know how this property can be changed?
I'm not seeing any way to update it even when logged in as an administrator.