I was just attempting to use the ArcGIS Online Assistant to copy content (a WebMap and associated WebApp) from my ArcGIS Online account to my Portal account. I followed the process - which is pretty straightforward - and both appeared to copy over to ArcGIS Online. The WebMap worked fine but upon opening the WebApp, a frowning face appears with the text "item does not exist or is inaccessible" underneath it. For all intents and purposes, the WebApp settings and sharing are identical to my other existing Portal WebApps. Has anyone experienced this before? The only option looks to be recreating the WebApp in Portal now.