Since many different problems can cause this error page, I would strongly recommend the following in order to determine the root cause quickly and easily, without meddling with Azure.
You can enable extremely helpful developer friendly error messages at startup by setting the .UseSetting(“detailedErrors”, “true”) and .CaptureStartupErrors(true) actions in your Program.cs file.
With the above settings publish your application to azure. Once you identify the root cause and resolve your issue, These above settings should be removed as soon as your troubleshooting is complete so as not to expose your application to malicious attacks.
Hope this helps someone out there.