What could possibly have caused this error?
Server Error in '/' Application.
Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. Access is denied.
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 'AjaxControlToolkit' or one of its dependencies. Access is denied.
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.
Assembly Load Trace: The following information can be helpful to determine why the assembly 'AjaxControlToolkit' could not be loaded.
WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
Stack Trace:
[FileLoadException: Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. Access is denied.]
System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +0
System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +210
System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +242
System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +17
System.Reflection.Assembly.Load(String assemblyString) +35
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +122
[ConfigurationErrorsException: Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. Access is denied.]
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +12759734
System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +503
System.Web.Configuration.AssemblyInfo.get_AssemblyInternal() +142
System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +334
System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath) +203
System.Web.Compilation.BuildManager.ExecutePreAppStart() +152
System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +1151
[HttpException (0x80004005): Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. Access is denied.]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +12880068
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +159
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +12721257
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18033