Add troubleshooting for regional endpoints

Add troubleshooting for regional endpoints

Author: niallzato

src/connections/destinations/catalog/actions-intercom-web/index.md

@@ -40,3 +40,11 @@ Intercom Web (Actions) provides the following benefits over the classic Intercom
 7. Enable the destination and configured mappings.
 
 {% include components/actions-fields.html settings="true"%}
+
+## Troubleshooting
+
+### Requests to Intercom return a 404 response
+If you are seeing 404 responses in your browser network tab, it's likely you have run into one of two issues:
+
+- You have set the wrong App ID in the Segment settings UI.
+- You have set the wrong Regional Data Hosting value in the Segment settings UI. Regiaonal endpoints are gated on plan level by Intercom, so you may not have access to EU data hosting.