The ...dynamics.com/api/data/v9.0/contacts
endpoint and all other /api
endpoints in our on-site Microsoft Dynamics virtual machines returns 500 errors.
I do not think it is an authorization issue. In the Azure portal I've registered an app and am using the client/app id which was also put into Dynamics as Admin. I'm able to get an OAuth token, no problem. The app has full AD and Dynamics admin permissions that are granted in Azure.
Whenever I try any of the /api
endpoints the IIS web server just returns a 500. I can see the 500 error in the IIS log but it is non-descriptive. Just shows the standard IIS log record with IP address and status code.
I have also looked at the Event Viewer in which I see nothing at all. I do not see anything in the Windows logs -> Application list for a corroborating date and time stamp.
What would at least help is if I can just get some detail on the error I'm getting. But I don't know where to look. I'm guessing it is some error being thrown in the API code call.
I've tried using Postman and a PHP library but both are getting the 500 errors. I don't think it is my end.