Error while loading GraphicsMagick.NET-x64 into a Web App (IIS) - graphicsmagick

Question

I'm getting a FileNotFoundException while loading GraphicsMagick.NET-x64 from my web app. The error I get is this one:
[FileNotFoundException: Could not load file or assembly 'GraphicsMagick.NET-x64.DLL' or one of its dependencies. The specified module could not be found.]
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 'GraphicsMagick.NET-x64.DLL' or one of its dependencies. The specified module could not be found.]
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) [phone]
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 'GraphicsMagick.NET-x64.DLL' or one of its dependencies. The specified module could not be found.]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) [phone]
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +159
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) [phone]
Until here it seemed as a typical missing reference. Enabling FusionLog says that the loading was correct:
*** Assembly Binder Log Entry (5/4/2015 # 1:59:21 PM) ***
The operation was successful.
Bind result: hr = 0x0. The operation completed successfully.
Assembly manager loaded from: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll
Running under executable c:\windows\system32\inetsrv\w3wp.exe
--- A detailed error log follows.
=== Pre-bind state information ===
LOG: User = MYDOMAIN\myuser
LOG: DisplayName = GraphicsMagick.NET-x64
(Partial)
WRN: Partial binding information was supplied for an assembly:
WRN: Assembly Name: GraphicsMagick.NET-x64 | Domain ID: 2
WRN: A partial bind occurs when only part of the assembly display name is provided.
WRN: This might result in the binder loading an incorrect assembly.
WRN: It is recommended to provide a fully specified textual identity for the assembly,
WRN: that consists of the simple name, version, culture, and public key token.
WRN: See whitepaper http://go.microsoft.com/fwlink/?LinkId=109270 for more information and common solutions to this issue.
LOG: Appbase = file:///D:/Inetpub/64bit/contentmanagement/
LOG: Initial PrivatePath = D:\Inetpub\64bit\contentmanagement\bin
LOG: Dynamic Base = C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\contentmanagement\74df6702
LOG: Cache Base = C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\contentmanagement\74df6702
LOG: AppName = 31019969
Calling assembly : (Unknown).
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: D:\Inetpub\64bit\contentmanagement\web.config
LOG: Using host configuration file: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet.config
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/contentmanagement/74df6702/31019969/GraphicsMagick.NET-x64.DLL.
LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/contentmanagement/74df6702/31019969/GraphicsMagick.NET-x64/GraphicsMagick.NET-x64.DLL.
LOG: Attempting download of new URL file:///D:/Inetpub/64bit/contentmanagement/bin/GraphicsMagick.NET-x64.DLL.
LOG: Assembly download was successful. Attempting setup of file: D:\Inetpub\64bit\contentmanagement\bin\GraphicsMagick.NET-x64.dll
LOG: Entering download cache setup phase.
LOG: Assembly Name is: GraphicsMagick.NET-x64, Version=1.0.0.0, Culture=neutral, PublicKeyToken=ee2094eb40f5ea47
LOG: A partially-specified assembly bind succeeded from the application directory. Need to re-apply policy.
LOG: Using application configuration file: D:\Inetpub\64bit\contentmanagement\web.config
LOG: Using host configuration file: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet.config
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config.
LOG: Post-policy reference: GraphicsMagick.NET-x64, Version=1.0.0.0, Culture=neutral, PublicKeyToken=ee2094eb40f5ea47
LOG: GAC Lookup was unsuccessful.
LOG: Binding succeeds. Returns assembly from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\contentmanagement\74df6702\31019969\assembly\dl3\978ebf9e\8e04cef5_4b86d001\GraphicsMagick.NET-x64.dll.
LOG: Assembly is loaded in default load context.
I'm not really sure what am I missing here, or if there is any way to get more/better logs.
The odd thing is that this GraphicsMagick error just happens on my Production environment (Development and Pre-production work OK). I compared (IIS mostly) configurations, side by side, feature by feature and saw now difference.
Whenever I launch the site from VS2013 (64-bit IIS Express), it also works well.
Environment
Application Pool:
Framework: v4
Enable 32-Bit Applications: false
IIS: 7.5

Answer 1

Ok, the problem was that we had not installed Visual C++ Redistributable for Visual Studio as GraphicsMagick's codeplex page clearly indicates... Thanks ProcessMonitor for your help!
BTW, I would have expected that Fusion logs produce all assembly loading related traces/errors, but that is not the case.