Some editable layers cannot participate in a map topology

Description

Upon opening the Map Topology dialog box and checking layers in the list to be included in the topology, some of the layers have been unchecked when the dialog box is reopened. In addition, those layers are not affected by any shared feature edits.

Cause

Some layers are being projected on the fly.

Solution or Workaround

1. To change the coordinate system of the data frame, such as to make the data frame match a particular layer, see Specifying a coordinate system.
   

   Note:
   Stop the edit session before doing this.

   
   
2. To project a layer to match other layers, use the Project geoprocessing tool: Project (Data Management).
3. Once all the projections match, start an edit session.
4. Open the Map Topology dialog box again, and check the layers that will participate in the map topology. The layers will now be affected by shared edits.