SharePoint Online Provider Hosted Low Trust Apps hosted on IIS not working

Question

I am trying to create a provider hosted app in SharePoint Online trial tenant with the remote web of the app hosted in IIS of an on premise server. It is a simple Hello World app, with the remote web as simple ASP.net Form web project.

The App is registered in the tenant using the appregnew.aspx. After this the client id and secret are used to publish the web project and the App project. The web project is now deployed on an on-premises server IIS(internet access open) and the APP is published in App catalog and installed in the site collection.

Post APP installation, when I open the app, its redirecting to the remote web but there it fails with an error

"An error occurred while processing your request."

The same app works like a charm, when I point it to a developer site in the same tenant.

Am I missing any steps to get the provider hosted apps working?

Answer 1

I am writing as an answer since I can't comment.

"The same app works like a charm, when I point it to a developer site in the same tenant." - Do you mean you give remote URL in your App manifest the URL of another site in your tenant?

Please note couple of things with regard to the remote Web App component of provider hosted Application:

1. It must be accessible over internet using the URL you mention in App manifest, since it will be redirected to from SPOnline (Azure service bus is another option but that is a different topic)
2. It must support HTTPS. Adding https support to your server is not difficult as you can generate certificates (Makecert.exe). However, the difficult part is that these certificates must also be trusted by SPOnline which doesn't happen for test certificates. One option here is to run your web component on Azure which has certificates that are trusted by SPOnline

Thanks.