On newly published. Could not load file or assembly 'mvcappname' or one of its dependencies. Access is denied

Question

Starting a couple of days ago any MVC project that I publish returns the below error.

I'm publishing to IIS8 on Server 2012R2 on our LAN. All existed sites work fine. The projects build and run fine on my develop pc. If I publish a project that I haven't changed to a new site I get the same error. If I overwrite an existing site I get the error as well. The contents of a working site and a nonworking appear to be the same.

Server Error in '/mvcappname' Application.
Could not load file or assembly 'RSStatus' 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 'mvcappname' 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 'mvcappname' 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 'mvcappname' 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) +232
   System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +113
   System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +23
   System.Reflection.Assembly.Load(String assemblyString) +35
# System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +49

[ConfigurationErrorsException: Could not load file or assembly 'mvcappname' or one of its dependencies. Access is denied.]
   System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +762
   System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +259
   System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +167
   System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +238
   System.Web.Compilation.BuildManager.GetPreStartInitMethodsFromReferencedAssemblies() +78
   System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +334
   System.Web.Compilation.BuildManager.ExecutePreAppStart() +178
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +746

# [HttpException (0x80004005): Could not load file or assembly 'mvcappname' or one of its dependencies. Access is denied.]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +552
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +122
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +737

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4494.0

I've checked the user permissions of several existing and new sites and they all seem to match. I have restarted the server as well as my pc. If I copy the 'site name dll' from a working site to a non working site then I can login to the site. I need help tracking this down. I'm told nothing has changed on the server. I am up to date with vs2022.

Thanks for any help.

Answer 1

ThreatLocker was installed on the server last week. It locks files if the hash value changes. I found out the hard way.