I've got a web map that's being used in Collector. All the layers come from ArcGIS Server 10.4.1 services. Everything seems to work in an "online" mode and in AGOL web map itself but when I click the "download" button for the map in Collector, the download progress bar hangs about half way and never seems to be able to finish. It seems to be hanging up on my cached basemap service because for a while (and I get get it to do this anymore) but when I went to download the map onto Collector it asked me which basemap I wanted to use. If I chose an esri basemap, the whole thing downloaded just fine but if I chose my basemap, it hung up about half way through the process.
What's going on with my basemap that it won't download?