Solution

Do the following to make a field visible:

In ArcGIS for Desktop:

1. In the Table Of Contents pane of ArcMap, right-click the layer that contains the field and click Properties.
2. Click the Fields tab.
3. Check the box next to the field to make it visible.
4. Click OK to close the Layer Properties dialog box.
5. Save your map and republish.

In ArcGIS Pro:

1. In the Contents pane of the map, right-click the layer that contains the field, point to Design, and click Fields.
2. Check the Visible box for the field.
3. Save your map and republish.