Layer is not added to ArcMap when dropped below an expanded image service in the table of contents

Description

If you try to drag and drop a layer below an expanded image service layer, the dropped layer does not get added and the table of contents (TOC) switches to the Source tab.

Cause

Image service layers are implemented as a group of sub-layers. This composite layer type does not implement add or remove items; thus, ArcMap does not recognize the area below them in the TOC as a drop zone for adding layers to the map.

Solution or Workaround