I've included both error messages that show up in the system log, this is a fresh install of v2.3 with no sample data populated. These two errors also show up on the site that I upgraded from v2.2 to v2.3.
SQL server 2005 sp4
Error 1 *********************
Log level: Error
Short message: Cannot redirect after HTTP headers have been sent.
Full message: System.Web.HttpException (0x80004005): Cannot redirect after HTTP headers have been sent. at System.Web.HttpResponse.Redirect(String url, Boolean endResponse, Boolean permanent) at System.Web.HttpResponseWrapper.Redirect(String url, Boolean endResponse) at System.Web.Mvc.RedirectToRouteResult.ExecuteResult(ControllerContext context) at System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<>c__DisplayClass1e.<InvokeActionResultWithFilters>b__1b() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)
IP address: 192.168.111.52
Customer: John Smith (View)
Page URL: http://test.servehttp.com/admin/common/restartapplication
Referrer URL: http://test.servehttp.com/Admin/Log/List
Created on: 11/23/2011 9:46:11 PM
Error 2*****************
Log level: Error
Short message: Cannot redirect after HTTP headers have been sent.
Full message: System.Web.HttpException (0x80004005): Cannot redirect after HTTP headers have been sent. at System.Web.HttpResponse.Redirect(String url, Boolean endResponse, Boolean permanent) at System.Web.HttpResponseWrapper.Redirect(String url, Boolean endResponse) at System.Web.Mvc.RedirectToRouteResult.ExecuteResult(ControllerContext context) at System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<>c__DisplayClass1e.<InvokeActionResultWithFilters>b__1b() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) at System.Web.Mvc.Controller.ExecuteCore() at System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) at System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) at System.Web.Mvc.MvcHandler.<>c__DisplayClass6.<>c__DisplayClassb.<BeginProcessRequest>b__5() at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.<MakeVoidDelegate>b__0() at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.MvcHandler.<>c__DisplayClasse.<EndProcessRequest>b__d() at System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) at System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) at System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) at System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
IP address: 192.168.111.52
Customer: John Smith (View)
Page URL: http://test.servehttp.com/admin/common/restartapplication
Referrer URL: http://test.servehttp.com/Admin/Log/List
Created on: 11/23/2011 9:46:11 PM