The Planarize Lines option is disabled in the Advanced Editing toolbar

Description

In some instances, the Planarize Lines option is disabled while working with the Advanced Editing toolbar in ArcMap.

Cause

The Planarize Lines option is disabled if the features selected in the map layout include polygon or point features. This option is available only when line features are selected, as it splits selected line features where they intersect and removes overlapping line segments.

Solution or Workaround

To resolve this issue in ArcMap, clear the selected features using the Clear Selected Features tool and select only line features.

Note:
To avoid confusion, Esri recommends turning off the polygon or point layer before selecting the line features in the Table Of Contents. Refer to ArcMap: Turning a layer on or off for more information.

The image below shows the Planarize Lines option is enabled and can be used to split the lines.