# Microsoft.AspNetCore.Mvc.Infrastructure

``` diff
 namespace Microsoft.AspNetCore.Mvc.Infrastructure {
     public class AmbiguousActionException : InvalidOperationException {
-        protected AmbiguousActionException(SerializationInfo info, StreamingContext context);
+        [ObsoleteAttribute("This API supports obsolete formatter-based serialization. It should not be called or extended by application code.", DiagnosticId="SYSLIB0051", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
+        protected AmbiguousActionException(SerializationInfo info, StreamingContext context);
     }
 }
```

