Your portal version does not support integrated mesh modifications. Integrated mesh modifications are not supported for ArcGIS Enterprise 10.8.1 and earlier. The modification is not visible in Scene Viewer.
To learn more about modifications, see Modify an integrated mesh layer.
Solution
- Do nothing. The modification appears when the scene is opened in an ArcGIS Pro project.
More information
For more information, see Share a web scene and Analyze your GIS resource.