An offline map can still include references to these online-only layers, allowing the layers to be accessed and displayed whenever a network connection is available. Some layers do not support being taken offline (either they have not been offline-enabled, or the type of layer does not support being taken offline). You can check the layer Capabilities and table Capabilities to determine which layer or table cannot be taken offline, and why. When true, the has Errors property indicates that one or more layers or tables cannot be taken offline due to an error. Get the OfflineMapCapabilities object by calling the get Offline M a p Capabilities Async method on OfflineMapTask. This can help identify layers or tables that are missing in the offline map that is generated. You should check which layers and tables in the web map can be taken offline by examining the web map's offline capabilities.
Your ArcGIS Runtime app can use a web map while it has no internet connection, by first downloading an offline map from the web map.