html error 500

5 Answers. form login facebook html According to the TraceLog file that you provided you have a problem in your web. kingdom manga 500 config file An exception message is C:\Users\teilmann\source\Nuheat\oj web\oj web main\web config ( 112) :Cannot add duplicate collection entry of type "mimeMap" with unique key attribute "fileExtension" set to " json"