Map navigation tools in a layout view are disabled in ArcGIS Pro

Description

In ArcGIS Pro, when attempting to navigate a map in a layout view, the map navigation tools in the Map group are disabled as shown in the image below.

Cause

This issue occurs when the display constraint of the map frame is set to 'Fixed extent'. Navigation is unavailable because this option sets the map frame to the map extent. Refer to ArcGIS Pro: Standard map frame constraints for more information.

Solution or Workaround

1. Open the ArcGIS Pro project.
2. Click the Layout tab to activate the layout view. The tab color turns blue.

3. In the Contents pane, right-click Map Frame, and click Properties.
4. In the Format Map Frame pane, click the Display Options tab, and expand the Constraint node. Select None from the drop-down list.

The image below shows the map navigation tools enabled in ArcGIS Pro.