I run a site on Umbraco 7.1.3 and a SQL server database, both in Azure platform services.

The site has been functionationg smoothly running on webforms (upgraded from umbraco 4). Now I have added API functionality, so the environment is mixed between webforms and MVC. I got the API to work, but at the same time the backoffice stopped serving content and gives the error message "Failed to retrieve data for application tree content".

I'm guessing the routing is screwed up in the mixed environment. Anyone here that have experience in mixing webforms and MVC in Umbraco or have seen this error message?

My API controller looks like this:

namespace Externweb.Controllers
{
    [PluginController("News")]
    public class NewsController : UmbracoApiController
    {
        /// <summary>
        /// Get top 20 member news for all rings
        /// </summary>
        /// <returns>list of news in json</returns>
        public List<NewsModel> GetMemberNews()
        {
            var newsList = new List<NewsModel>();

            foreach (var node in Umbraco.Content(1101).Descendants(3).Where("localMembers == true").OrderBy("UpdateDate desc").Take(20))
            {
                var news = ReadNewsNode(node);

                newsList.Add(news);
            }

            return newsList;
        }
}