Your basemap layer contains a layer that references a web service. Issues with network connectivity or load on a service may negatively affect the performance of this layer.
Solutions
- Do nothing. You can accept the display difference as is.
- Alternatively, you can rebuild your map to use local data or reference a different web service with better performance.
More information
This message is telling you that a layer in your basemap layer references a web service, and the layer could experience slower performance. You should evaluate the performance of the layer, as it may be affected by server load and network traffic.