In some instances, attempting to delete an item on the My Content page in Portal for ArcGIS returns the following error message in the Delete window:
Error: The following items can’t be deleted because they are delete protected or have dependent items. <item_name>
Occasionally, an information icon is also displayed beside the item name. Hovering over the icon displays the following error message:
Error: Unable to delete item. This service item has a related Service item.
Depending on the cause, use one or both of the workarounds below to resolve the issue. In this article's example, the Californian_Cities hosted feature layer is the item to delete, and the Californian_Cities_View is dependent on Californian_Cities.
In Portal for ArcGIS, enable the option to delete the item
In Portal for ArcGIS, delete all the contents dependent on the item
The image below shows the Californian_Cities hosted feature layer successfully deleted after the dependent item, Californian_Cities_View, is deleted.