I'm developing an app for a non-profit who needs to have offline maps of specific regions in the state. I've registered my app with a basic license, and I have put the code in my app to initialize it. The problem I am having is that when I try to load one of the tiledbasemaps.arcgis.com maps, my map is blank. If I substitute http://sampleserver6.arcgisonline.com, it works, but it has limited levels of detail (as one would expect from a example server). Is there a trick to getting content from the tiledbasemaps.arcgis.com servers as outlined in the iOS SDK guide? I have mimicked the code in the DownloadTileCacheSample example, only changing the URL. The URL I'm using is http://tiledbasemaps.arcgis.com/arcgis/rest/services/World_Street_Map/MapServer.