Error: The Create Feature task cannot be completed. The first vertex could not be snapped to a network edge
Error Message
When creating a turn feature on a network dataset using one of the snapping tools from the Snapping toolbar, the following error message is returned:

For more information on turns in a network dataset, refer to the following ArcGIS Web Help page: Turns in the network dataset.
Cause
The error occurs due to one of the following reasons:
- The network edge source layer is not turned on in the map
- A connection cannot be formed with the network dataset because the turn feature is either overshooting or undershooting the street lines.
- The turn feature class is ZM-enabled.
Solution or Workaround
If Option A does not work, the problem may be a snapping issue. In that case, use Option B. If the turn feature class is ZM-enabled, use Option C.
Option A - Turn on the network edge source layerEnsure the network edge source layer (the lines which represent the streets) is turned on in the map. Turn features must be snapped to the network edge source, instead of the network edges themselves.

Option B - Use the Edge Snapping tool
Use the Edge Snapping tool from the Snapping toolbar when creating turn features.

For more information on creating a turn feature, refer to the following ArcGIS Web Help topic: Creating a turn feature.
Option C - Create a copy of the turn feature class with the M-values disabled
Note: Z-values can be enabled but cannot be both Z and M enabled.
- In the Catalog window, navigate to System Toolboxes > Conversion Tools > To Geodatabase > Feature Class to Feature Class.
- Specify the input features, output location, and output feature class in the Feature Class to Feature Class tool.
- Click Environments to open the Environment Settings window.
- Expand M Values and set Output has M Values to Disabled.
- Expand Z Values and set Output has Z Values to Disabled.
- Click OK, and run the tool.
- Rebuilt the network dataset with the new turn feature class.
Related Information
- How To: Prepare data for use with the Network Analyst extension
- ArcGIS Help: Network elements
- ArcGIS Help: Create Turn Feature Class
- ArcGIS Help: Types of evaluators used by a network
Last Published: 8/29/2017
Article ID: 000012868
Software: ArcMap 10.5.1, 10.5