I am working on migrating our sharepoint on-premises to Office 365. now i manage to migrate the list and libraries and site settings using third party tool.

Next step is that i need to re-implement our Event Receivers to work as Remote ER. so i tried to create a very simple test RER,as my first RER experience, but i fail to do so.

I tried using Provider-hosted add-in and then using SP-hosted add-in without any success, as follow:-

Using Provider-Hosted Approach

1. I created a developer site collection.

2. Then i open visual studio 2015 professional, i create a new sharepoint add-in

3. I chose type as provider-hosted add-in.

4. And type as SharePoint-online:-

5. type using MVC.

6. Authentication as AZURE.

7. Then i right click on the solution>>i add a new remote event receiver.

8. Then i define that the event is item adding on custom lists.

9. Then i added the following code inside my RER, to update the title of the item to be equal to “updated title”, as follow:-

public class RemoteEventReceiver1 : IRemoteEventService     {         /// <summary>         /// Handles events that occur before an action occurs, such as when a user adds or deletes a list item.         /// </summary>         /// <param name="properties">Holds information about the remote event.</param>         /// <returns>Holds information returned from the remote event.</returns>         public SPRemoteEventResult ProcessEvent(SPRemoteEventProperties properties)         {             SPRemoteEventResult result = new SPRemoteEventResult();              using (ClientContext clientContext = TokenHelper.CreateRemoteEventReceiverClientContext(properties))             {                 if (clientContext != null)                 {                     if (properties.EventType == SPRemoteEventType.ItemAdding)                     {                         result.ChangedItemProperties.Add("Title", "updated title");                      }                     //  clientContext.Load(clientContext.Web);                     //  clientContext.ExecuteQuery();                 }             }              return result;        }         /// <summary>         /// Handles events that occur after an action occurs, such as after a user adds an item to a list or deletes an item from a list.         /// </summary>         /// <param name="properties">Holds information about the remote event.</param>         public void ProcessOneWayEvent(SPRemoteEventProperties properties)         {             using (ClientContext clientContext = TokenHelper.CreateRemoteEventReceiverClientContext(properties))             {                 if (clientContext != null)                 {                     clientContext.Load(clientContext.Web);                     clientContext.ExecuteQuery();                 }             }         }     } 

10. Then i build and run my application, where i got a page to trust the app.

11. After trusting it, i was redirected to an asp.net MVC web application. Where the MVC url will be as follow:-

https://localhost:44356/?SPHostUrl=https//*****

Using SP-Hosted App

1. I create a new SharePoint add-in

2. I select it as SharePoint-Hosted app.

3. version as SharePoint-online.

4. after that i right click on the project and i add a new item of type RER. i specify to run when list item are being added on custom lists(similar as above).

5. inside the RER i entered this code (similar to the above)

SPRemoteEventResult result = new SPRemoteEventResult();              using (ClientContext clientContext = TokenHelper.CreateRemoteEventReceiverClientContext(properties))             {                 if (clientContext != null)                 {                     if (properties.EventType == SPRemoteEventType.ItemAdding)                     {                         result.ChangedItemProperties.Add("Title", "updated title");                      }                     //  clientContext.Load(clientContext.Web);                     //  clientContext.ExecuteQuery();                 }             }              return result; 

6. Now i select the AppManifist.xml file >> right click on it >> view code >> i define the security as Internal

<AppPrincipal>     <Internal />   </AppPrincipal> 

7. then inside the web.config i commented out the client ids:-

<appSettings>     <!--<add key="ClientId" value="" />     <add key="ClientSecret" value="kB1iTFbzhSfByM5aeligELKoM8uaTtKl02pNmIYd1BM=" />-->   </appSettings> 

8. then i build and run the project.

Now inside my DEV site collection i already have a custom list, where i added a new item but its title did not change, i tried this when i deploy the Provider-Hosted add-in and then when i deploy the SharePoint-Hosted add-in .
so seems my RER did not fire… can anyone advice what could be causing my provider hosted add-in OR my sharepoint-hosted add-in which contain the RER to not get fired when items are being added?? although i followed the same steps as the one used on many samples and tutorials.