Downloading a map produces this error in the logs: Error downloading map: Premature end of content-length delimited message body.
I narrowed down the issue to a layer in the map that is a secured service. The layer has stored credentials. If I switch the layer with the same service and don’t store credentials, which prompts me to enter credentials when viewing the map, the download is successful. Thus, the layer is set-up correctly to allow for offline maps, its just something about the storing the credentials that prevents Field Maps from downloading.
This is a pretty big issue for us because we don’t want Field Map users to have to enter their credentials to the secured service each time they want to open the map.
I didn’t experience this issue in Collector.