Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://localhost:xxxxx' is therefore not allowed access

While developing an adal.js app with OData in IISExpress, I'm getting the following error:

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://localhost:44315' is therefore not allowed access

Turns out the problem is that I needed to include the CORS package from Microsoft:

Install-Package Microsoft.AspNet.WebApi.Cors

Once that's in there, I also need to enable CORS using the 'EnableCors' extension method on my HttpConfiguration.

Using adal.js and getting error AADSTS65001: The user or administrator has not consented to use the application with ID '....'

It turns out that you have to actually go in and give your javascript web client permissions to access the web api application in the Azure Active Directory management portal. Go figure.

Using adal.js and getting error AADSTS70005: response_type="token" not supported

I've recently started using adal.js with OData in an AngularJS 1.5 application and been getting this error with attempting to connect my client-side XHR requests to my Web API application.

Following the advice here, changing the AAD manifest of the AngularJS web client from this:

"oauth2AllowImplicitFlow": false

... to this:

"oauth2AllowImplicitFlow": true

... seems to have solved the problem.