Could not load file or assembly ‘file:///C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\ asp.net vs2010

Yesterday my project was running smoothly but today I'm facing an error. Here are the details:

Could not load file or assembly 'file:///C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\parktms\c8392404\1ba3bab5\App_Web_login.aspx.6cc23264.lmj8uym6.dll' or one of its dependencies. The handle is invalid. (Exception from HRESULT: 0x80070006 (E_HANDLE))
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details:

System.IO.FileLoadException: Could not load file or assembly 'file:///C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\parktms\c8392404\1ba3bab5\App_Web_login.aspx.6cc23264.lmj8uym6.dll' or one of its dependencies. The handle is invalid. (Exception from HRESULT: 0x80070006 (E_HANDLE))

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[FileLoadException: Could not load file or assembly 'file:///C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\parktms\c8392404\1ba3bab5\App_Web_login.aspx.6cc23264.lmj8uym6.dll' or one of its dependencies. The handle is invalid. (Exception from HRESULT: 0x80070006 (E_HANDLE))]
System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +0
System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +39
System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection, Boolean suppressSecurityChecks) +132
System.Reflection.Assembly.Load(AssemblyName assemblyRef, Evidence assemblySecurity) +28
System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly() +93
System.Web.Compilation.BuildProvider.CreateBuildResult(CompilerResults results) +65
System.Web.Compilation.TemplateControlBuildProvider.CreateBuildResult(CompilerResults results) +36
System.Web.Compilation.BuildProvider.GetBuildResult(CompilerResults results) +16
System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) +8967378
System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) +320
System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) +111
System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean throwIfNotFound) +125
System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(VirtualPath virtualPath, Type requiredBaseType, HttpContext context, Boolean allowCrossApp) +52
System.Web.UI.PageHandlerFactory.GetHandlerHelper(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) +31
System.Web.UI.PageHandlerFactory.System.Web.IHttpHandlerFactory2.GetHandler(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) +40
System.Web.HttpApplication.MapHttpHandler(HttpContext context, String requestType, VirtualPath path, String pathTranslated, Boolean useAppConfig) +167
System.Web.MapHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +128
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184

Version Information:

Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.225

why am I having this problem and how do I get rid of it?