Could not load file or assembly 'Microsoft.Azure.Documents.ServiceInterop' or one of its dependencies. Could not find or load a specific file. (Exception from HRESULT: 0x80131621)]

[IanKemp]

Describe the bug

As per the title.

Our .NET Framework 4.6.1 web app was using version 1.22.0 of this package without issue. We updated to 2.11.2 (latest at the time of writing). After deploying the app to Azure, we started receiving this exception.

Manually deleting Microsoft.Azure.Documents.ServiceInterop.dll from the bin\ directory in Azure (via the Kudu frontend) resolved the issue. This was a shot in the dark that worked, and I'd like to understand why.

The app is set to build as AnyCPU and the Azure App Service is set to use .NET V4.7/64-bit so I don't believe that bitness is an issue here.

Additional context

Generic FileNotFoundException stack trace:

Server Error in '/' Application.
Could not load file or assembly 'Microsoft.Azure.Documents.ServiceInterop' or one of its dependencies. Could not find or load a specific file. (Exception from HRESULT: 0x80131621)
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 'Microsoft.Azure.Documents.ServiceInterop' or one of its dependencies. Could not find or load a specific file. (Exception from HRESULT: 0x80131621)

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 'Microsoft.Azure.Documents.ServiceInterop' 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 'Microsoft.Azure.Documents.ServiceInterop' or one of its dependencies. Could not find or load a specific file. (Exception from HRESULT: 0x80131621)]
   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) +225
   System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +110
   System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +22
   System.Reflection.Assembly.Load(String assemblyString) +34
   System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +48

[ConfigurationErrorsException: Could not load file or assembly 'Microsoft.Azure.Documents.ServiceInterop' or one of its dependencies. Could not find or load a specific file. (Exception from HRESULT: 0x80131621)]
   System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +725
   System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +247
   System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +157
   System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +226
   System.Web.Compilation.BuildManager.GetPreStartInitMethodsFromReferencedAssemblies() +73
   System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +319
   System.Web.Compilation.BuildManager.ExecutePreAppStart() +170
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +820

[HttpException (0x80004005): Could not load file or assembly 'Microsoft.Azure.Documents.ServiceInterop' or one of its dependencies. Could not find or load a specific file. (Exception from HRESULT: 0x80131621)]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +523
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +107
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +688

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.3535.0