If you are editing data in ArcMap, and you use a geoprocessing tool that either
- uses a layer that is being edited as input or
- creates data in the same workspace as the layer being edited,
the tool may return an error because it cannot modify the input data for the reasons described below.
First, a couple of definitions you need to know are presented here:
- Edit session: When you are editing data in ArcMap, you are said to be in an edit session.
- Edit workspace: This is the workspace containing the data currently being edited.
Overwriting existing data in the edit workspace
If you are in an edit session, existing data in the edit workspace cannot be overwritten by a tool, even if the geoprocessing options have been set to Overwrite the outputs of geoprocessing operations. Tools will stop execution and return an error.
Creating new data in the edit workspace
Creating new shapefiles
Shapefiles created in the edit workspace cannot be edited. You must first save your edits and end the edit session, then start a new edit session.
Updating existing data
When editing a feature class or table, you are not allowed to make schema changes. A schema change is a change to the fields, such as adding a new field (Add Field) or deleting existing fields (Delete Field). Tools that alter schemas will return an error message if the input is being edited.