This article was contributed by Esri Canada.
In ArcGIS Pro, attempts to overwrite a web layer hosted on ArcGIS Online returns the following error message:
Error: Overwrite Web Layer: The selected web layer does not have a name and cannot be overwritten.
This error occurs when attempting to overwrite a web layer (hosted feature service) that does not have a service definition in ArcGIS Online.
For example, ArcGIS Online does not create a service definition file when a zip file (containing the feature layer) is published directly to ArcGIS Online. Hence, attempts to overwrite the web layer return the Overwrite Web Layer error message.
Note: In older versions of ArcGIS Online, a service definition could be deleted. However, this is no longer possible, as a protection check was implemented to prevent deletion of a service definition referenced by a hosted feature service.
There are two possible solutions for this issue, depending on the cause.
If the web layer (featured service) was initially published using ArcGIS Online, the web layer can be overwritten. To do so, refer to ArcGIS Help: Overwrite hosted feature layers.
A service definition file is required to overwrite a hosted web layer. If the web layer (feature service) was initially published via ArcGIS Pro, and the service definition file is no longer present, republish the web layer as a new web layer. The republished web layer contains an associated service definition file in ArcGIS Online, allowing the web layer to be overwritten in the future.
For steps on how to overwrite a web layer in ArcGIS Pro, refer to ArcGIS Pro Help: Overwrite a web layer.