Add attachments to a related table

Overview:
The HTML5 viewer provides a menu option to add attachments to feature layers when available, but in some versions this option is not provided for related tables.  This workaround will let users add attachments to related tables as well.

Solution:

1. Ensure that the layer that is related to the table is included in your site, and ensure that your ArcGIS Server table has attachments and editing enabled.
2. If you have not already done so, navigate to Manager > Map > Add Map Service, and add the table to the site as a Feature Layer.
3. The table will not appear in the Layer List.  It will appear in the Map Services tab with a disabled checkbox.
4. Save your site.
5. Navigate to your site xml file. By default, this is located at: C:\Program Files (x86)\Latitude Geographics\Geocortex Essentials\Default\REST Elements\Sites\SITENAME\Site.xml
6. Make a backup of this file, then edit the original in a text editor like notepad.
7. Use CTRL + F and search for the table's ArcGIS REST endpoint URL in order to find its FeatureLayer tag in the xml file. It will look something like this: 

8. <FeatureLayer ConnectionString="url=http://servername/arcgis/rest/services/RelatedTableService/FeatureServer/1" DefaultAllowSymbolization="true" DisplayName="RelatedTable" Function="Operational" ID="2" ImpersonateWithActor="false" IncludeCopyright="false" IncludeInLayerList="false" InstantSearch="false" InstantSearchAttachments="false" IsExpanded="true" Opacity="1" OutFields="*" OverrideTemporalSettings="false" PasswordEncrypted="false" QueryMode="OnDemand" SearchNonTextFields="true" UseHttpAuthentication="false" Visible="false">

9. Change Visible="false" to Visible="true".
10. Save the site xml file.
11. Open your HTML5 viewer and select a feature that has a related record in the table.
12. Click on the related record.
13. The context menu for the related record will now have the "Attach a file or photo option".