Azure AD Error after editing manifest to enable availableToOtherTenants

Question

We are trying to deploy are web application and web API to a new Azure subscription associated with our corporate Azure AD account. However, when we attempt to modify the Azure AD manifest to enable the multi-tenant flag "availableToOtherTenants" and set the "knownClientApplications" client ID of our WebApp in our WebAPI manifest we get the following error after attempting to upload them:

ParameterValidationException=Invalid parameters provided; BadRequestException=Host name in property identifierUris is not on any verified domain of the company or its subdomain

Both the webapp and webapi are App Services in AzureAD and are using the .azurewebsites.net as the identifierUris in their manifests. We were not planning on registering a domain name for these services since these services are just for internal testing. The subscription the apps are deployed does appear to be associated with the directory the apps are registered in Azure AD, so why would it have a problem with these Uris?

Answer 1

From the helper text for App ID URI in the management portal:

The URI is used as a unique logical identifier for your app. The URI must be in a verified custom domain for an external user to grant your app access to their data in Microsoft Azure AD

That being said, since the App ID URI doesn't have any functional implications, you should still be able to do your testing by setting your App ID URI to something along the lines of:

http://<localhost_or_whatever>.<tenantName>.onmicrosoft.com 

But keeping your Reply URLs as they are pointing to your .azurewebsite.net URIs.

This should let you proceed with configuring your app as multi-tenant and do your testing with whatever site you want.