The Trim/Extend task could not be completed. The geometry has null Z values.

Error Message

This error occurs when extending a polyline feature that has z-values using the Extend/Trim Feature edit task:

"The Trim/Extend task could not be completed. The geometry has null Z values."

Cause

The vertex added to the edit sketch, in order to extend the feature, does not support z values.

Solution or Workaround