File upload error in MS Azure after custom domain was pointed to Azure server
MS support team helped to resolve the issue. I will post the steps to be followed. 


In your CMS Admin, Under Assets source -> 
File system path: images/
URL: http://example.azurewebsites.net/images
(Here the images directory is under public directory)
In Azure portal, Add the following App settings in Application setting of your App service:
key: WEBSITE_DYNAMIC_CACHE 
value: 0
Restart the Azure App service.