A feature class with categorical symbology loses the value field label when published to ArcGIS Online

Description

In some instances, a feature class that has data with categorical symbology loses the value field label when published to ArcGIS Online.
For example, in ArcMap, a feature class is symbolized based on a numeric field for the magnitude of earthquakes. The field name used for the symbology is 'Mtude', but it is changed to appear as 'Magnitude' in the Table Of Contents for legend purposes. When publishing the feature class to ArcGIS Online, the value field label reverts back to 'Mtude'.

Cause

This is a known issue. Please refer to the following defect, BUG-000091082.

Solution or Workaround

Note:
It is recommended to change the sharing permissions so that the feature service is not shared with anyone before editing the service definition.

1. Log in to www.arcgis.com with administrator credentials.
2. Click My Content and open the item details page for the feature service.
   
3. On the item details, click the drop-down arrow next to a layer name and select Service URL.
   

   Example:

   
   
   
   This opens a new page; the ArcGIS REST Services Directory page.
4. To get to the admin page for a service, modify the URL to the one displayed below, appending '/admin' between rest and services:
   
   

   http://services.arcgis.com/xxxx/ArcGIS/rest/services/servicename/FeatureServer/0

   
   becomes:
   
   

   http://services.arcgis.com/xxxx/ArcGIS/rest/admin/services/servicename/FeatureServer/0

   
   
   
5. Scroll to the bottom of the page, and click Update Definition.
   

   Example:

   
   
   
6. Change the value of the 'lastEditDate' key to null.
   

   Example:

   
   
   
7. Search for the field name in question, and click until 'alias' is found. (Press 'Ctrl' + 'F' and start searching for the field name). Change the alias from the displayed label to the desired label of the value field for the symbology of the feature service.
   

   Example:

   
   
   
8. Click Update Service Definition.
9. Go back to the 'My Content' page, and re-add the feature service to a new web map to have the changes persist in any related web applications.