The process cannot access the file ‘C:\inetpub\vhosts\httpdocs\assets\css\site.css’ because it is being used by another process.

[IOException: The process cannot access the file 'C:\inetpub\vhosts\httpdocs\assets\css\site.css' because it is being used by another process.]
   System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) +893
   System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost) +1217
   System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share) +123
   System.Web.Hosting.MapPathBasedVirtualFile.Open() +104
   System.Web.Optimization.BundleFile.ApplyTransforms() +61
   System.Web.Optimization.DefaultBundleBuilder.BuildBundleContent(Bundle bundle, BundleContext context, IEnumerable`1 files) +654
   System.Web.Optimization.Bundle.GenerateBundleResponse(BundleContext context) +188
   System.Web.Optimization.Bundle.GetBundleResponse(BundleContext context) +59
   System.Web.Optimization.BundleResolver.GetBundleContents(String virtualPath) +213
   System.Web.Optimization.AssetManager.EliminateDuplicatesAndResolveUrls(IEnumerable`1 refs) +441
   System.Web.Optimization.AssetManager.RenderExplicit(String tagFormat, String[] paths) +34
   ASP._Page_Views_Shared__Head_cshtml.Execute() in C:\inetpub\vhosts\httpdocs\Views\Shared\_Head.cshtml:3
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +252
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +148
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +122
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +136
   ASP._Page_Views_Shared__Root_cshtml.Execute() in C:\inetpub\vhosts\httpdocs\Views\Shared\_Root.cshtml:47
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +252
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +148
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +122
   System.Web.WebPages.<>c__DisplayClass40_0.<RenderPageCore>b__0(TextWriter writer) +309
   System.Web.WebPages.WebPageBase.Write(HelperResult result) +108
   System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action`1 body) +89
   System.Web.WebPages.WebPageBase.PopContext() +310
   System.Web.WebPages.<>c__DisplayClass40_0.<RenderPageCore>b__0(TextWriter writer) +309
   System.Web.WebPages.WebPageBase.Write(HelperResult result) +108
   System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action`1 body) +89
   System.Web.WebPages.WebPageBase.PopContext() +310
   System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +375
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +88
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +775
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +775
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +81
   System.Web.Mvc.Async.<>c__DisplayClass3_1.<BeginInvokeAction>b__1(IAsyncResult asyncResult) +188
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +38
   System.Web.Mvc.<>c.<BeginExecuteCore>b__152_1(IAsyncResult asyncResult, ExecuteCoreState innerState) +26
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +73
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +52
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +39
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +38
   System.Web.Mvc.<>c.<BeginProcessRequest>b__20_1(IAsyncResult asyncResult, ProcessRequestState innerState) +40
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +73
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +38
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +602
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +195
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +128