IndexOutOfRangeException when using slash to define IP range

[achobanov]

Exception is thrown in BeginExecute method. Relevant stack trace:

[IndexOutOfRangeException: Index was outside the bounds of the array.]
   MvcThrottle.Bits.GetBitMask(Int32 sizeOfBuff, Int32 bitLen) +165
   MvcThrottle.IPAddressRange..ctor(String ipRangeString) +385
   MvcThrottle.IpAddressParser.ContainsIp(List`1 ipRules, String clientIp) +256
   MvcThrottle.ThrottlingFilter.IsWhitelisted(RequestIdentity requestIdentity) +333
   MvcThrottle.ThrottlingFilter.OnActionExecuting(ActionExecutingContext filterContext) +327
   System.Web.Mvc.Async.AsyncInvocationWithFilters.InvokeActionMethodFilterAsynchronouslyRecursive(Int32 filterIndex) +176
   System.Web.Mvc.Async.AsyncInvocationWithFilters.InvokeActionMethodFilterAsynchronouslyRecursive(Int32 filterIndex) +651
   System.Web.Mvc.Async.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__31(AsyncCallback asyncCallback, Object asyncState) +58
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +14
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters, AsyncCallback callback, Object state) +197
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__19(AsyncCallback asyncCallback, Object asyncState) +743
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +14
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +343
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1c(AsyncCallback asyncCallback, Object asyncState, ExecuteCoreState innerState) +25
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +465
   System.Web.Mvc.Controller.<BeginExecute>b__14(AsyncCallback asyncCallback, Object callbackState, Controller controller) +18
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +20
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +374

Range seems to work fine with - delimiter.