Problem: Red X Appears next to Basemap Layers in the Table of Contents

Description

When a basemap layer is added to a map document (.mxd file) in ArcMap, a red X appears next to the basemap layer checkbox in the Table Of Contents. The basemap is not visible in the data frame.
[O-Image] Red X basemap layer

Cause

This issue occurs when a layer, feature class, or other types of data with an undefined spatial reference are added to ArcMap before adding the basemap layer. Data with an undefined spatial reference has no projection or coordinate system.

The following error message window may appear when data sources have been added to the map that cause this issue.
[O-Image] Unknown Spatial Reference
Confirm the issue by right-clicking the newly added basemap layer and navigating to 'Analyze Basemap Layer'. The error 00002 appears, signifying the data frame does not have a spatial reference.
[O-Image] Analyze Basemap Layer

Solution or Workaround

Before adding a basemap layer, specify the coordinate system of the data frame. Use the following documentation, ArcGIS Help: Specifying a coordinate system, for more information.

Article ID: 000012407

Software: