Solution

• Remove the layer from your document.
• Publish to a server other than ArcGIS Online hosted services and make sure that the custom feature is registered on this server.

More information

Custom features allow you to customize geodatabase behavior. For layers utilizing custom features to work as expected within a service, the custom feature must be available to the server. If the custom feature is not accessible by the server, the specialized behavior, or functionality, will be unavailable on the service.

ArcGIS Online allows you to publish GIS web services to an Esri-administered cloud environment. You don't have to install anything; you just sign in to your ArcGIS Online account. There are two types of services you can deploy:

• Feature services expose the geometry, attributes, and symbol information for vector GIS features. They are appropriate for displaying, querying, and editing your business data on top of web basemaps.
• Tiled map services expose a set of pregenerated map images (known as a map cache) that can be viewed as basemaps in a web mapping application. When you publish your service, you can also ask the server to create and store a cache of tiles. You can then bring the tiles into your web map by accessing the service's URL.

Using a combination of tiled map services and feature services in your application allows fast mapping while supporting query and editing operations.

ArcGIS Online hosted services are available through organizational subscriptions to ArcGIS Online. An advantage of using ArcGIS Online is that you don't have to install any server software or tune the services. The services run in an Esri-administered cloud environment in which the server automatically scales up to meet demand.