Uh oh....hope this wasn't a bad day for me to first try to test Collector for ArcGIS download/sync! My first map is configured for offline storage, but when I click the "Download" button, the download hangs at about 80%. No errors shown. After waiting a while (nearly a half hour), and the mobile device still indicates that a file is downloading, Collector says that the map has downloaded and offers the "Sync" option. When I try to open the map, I receive the following error "Map Opening Failed...The basemap for this offline map was not found. If you're storing the TPK's on an SDCARD, make sure it is currently inserted." Is there an issue with caching the ArcGIS Online provided imagery basemap?