Roxel.BuildTasks.EnsureBindingRedirects.MergeBindingRedirectsFromElements throws an exception if configuration/runtime/assemblyBinding/dependentAssembly/assemblyIdentity is missing a "culture" attribute.
I discovered this through an upgraded MVC3 -> MVC4 project. The MVC3 base template doesn't add a "culture" attribute and the conversion to MVC4 (via dropping/updating NuGet packages) doesn't rectify the problem if it already exists.
The output of the error is:
The "EnsureBindingRedirects" task failed unexpectedly.
System.NullReferenceException: Object reference not set to an instance of an object.
at Roxel.BuildTasks.EnsureBindingRedirects.MergeBindingRedirectsFromElements(IEnumerable`1 dependentAssemblies)
at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__20.MoveNext() Lion.Tooheys.Facebook