AJAX查询不调用REST API控制器方法

I have a REST API controller configured as follows. On button click "PlayersRegistration", the update function in javascript is called prorperly. But the problem is that the PostPlayers Method in the DefaultController class never gets called using success: function(data) statement in update function. Instead when I check on the console in the browser by inspecting elements, i see Internal Server Error 500. I don't know what's wrong. I have a REST API controller configured as foll