180902: Input features have different Z values. Input features must be at the same elevation.
Description
The tool creates features for one level at a time and requires the input polylines to be at the same elevation.
Solution
Do one of the following:
If the input feature layer includes polylines from more than one level, select features by attributes or set a definition query on the input polyline feature layer to include features from only one level, and run the tool again.
If the input feature layer includes polylines from one level but some features have a different z-value, select the features that are at a different z-value and run the Adjust 3D Z tool to move them to the same elevation as the other features. Then rerun the tool.