Could not load file or assembly 'LibSassHost.Native-32' or one of its dependencies. An attempt was made to load a program with an incorrect format.

[JonCubed]

It is working locally for me but when I try to run in on a remote server it fails with this stack trace. I have the visual c++ redistributable 2013 installed (x86 & x64) on the remote server, it looks to me like it is trying to use 32-bit version instead of 64-bit.

[Taritsyn]

Hello, Jonathan!

It seems, that the LibSass Host does not load one of the Visual C++ Redistributable 2013 assemblies.

How did you installed the Visual C++ Redistributable Packages for Visual Studio 2013: via installer or locally in bin directory?

[JonCubed]

Via the installer.

I noticed that locally the LibSassHost.Native-32.dll and LibSassHost.Native-64.dll are in a subfolder in bin but on remote they are in the bin folder. When I replicate this structure I get a different error. The flattening of the structure seems to occur during msbuild publish when it uses the _CopyWebApplicationLegacy Target when publishing the website

[06:30:44][_CopyWebApplicationLegacy] Copy
[06:30:44][Copy] Copying file from "C:\TeamCity\buildAgent\work\f487e2bbb61aedc4\packages\LibSassHost.0.4.1\content\LibSassHost.Native\LibSassHost.Native-32.dll" to "..\Binaries\_PublishedWebsites\WebApp\bin\LibSassHost.Native-32.dll".
[06:30:44][Copy] Copying file from "C:\TeamCity\buildAgent\work\f487e2bbb61aedc4\packages\LibSassHost.0.4.1\content\LibSassHost.Native\LibSassHost.Native-64.dll" to "..\Binaries\_PublishedWebsites\WebApp\bin\LibSassHost.Native-64.dll".

Not sure if it really makes a difference or not

[JonCubed]

Here is the other error I mentioned https://gist.github.com/JonCubed/47f071af5cfb56286a0e#file-stacktrace-libsasshost-2

[Taritsyn]

but on remote they are in the bin folder

This leads to error. You must restore the original folder structure.

Type 'System.Collections.Immutable.ImmutableStack`1[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]' in Assembly 'NewRelic.Providers.CallStack.AsyncLocal, Version=5.12.13.0, Culture=neutral, PublicKeyToken=f7f92cc5c2dc8743' is not marked as serializable.

This error has no relation to my library.

[JonCubed]

but on remote they are in the bin folder
This leads to error. You must restore the original folder structure.

fair enough

This error has no relation to my library.

If you continue down the stack trace there is an error with LibSassHost

[TypeInitializationException: The type initializer for '' threw an exception.]
LibSassHost.SassCompiler..ctor(IFileManager fileManager) +0
BundleTransformer.SassAndScss.Translators.SassAndScssTranslator.Translate(IList1 assets) +326 BundleTransformer.Core.Transformers.TransformerBase.Translate(IList1 assets, Boolean isDebugMode) +116
BundleTransformer.Core.Transformers.TransformerBase.Transform(IList1 assets, BundleContext bundleContext, BundleResponse bundleResponse, VirtualPathProvider virtualPathProvider, Boolean isDebugMode) +106 BundleTransformer.Core.Transformers.TransformerBase.Process(BundleContext bundleContext, BundleResponse bundleResponse, Boolean isDebugMode) +347 System.Web.Optimization.Bundle.ApplyTransforms(BundleContext context, String bundleContent, IEnumerable1 bundleFiles) +210

[Taritsyn]

I've seen that is on the bottom of stack. I just used wrong words, because all that is before line 31 is simply bewildering.

I think, that can close this issue, because it is a deployment error.

[starteleport]

@Taritsyn, I've got the same problem. Story is short: I've decided to update BundleTransformer from 1.9.34 to 1.9.89. After the update, I've started to get compilation errors (related to includes) on my scss files. After which, I've decided to update LibSassHost from 0.4.1 to 0.4.3. That's when I started to see this error message.

I can't believe this is deployment issue because it tries to load 32-bit dll into 64-bit w3wp.exe. Here is gist with fusion log (sorry, it's in Russian) and procmon dump that suggest that issue is with LibSassHost, and not with C++ Redistributable libs (it even does not try to read those).

Could you please help me figure out, what's going on?

[Taritsyn]

Hello, Nikolay!

Try to restart IIS, and then reinstall LibSassHost.

[starteleport]

@Taritsyn, I'm not sure what you mean by "reinstall LibSassHost", but I've tried many times, the most hard-core was to:

• Stop IIS
• Drop everything in site root directory
• Drop everything in Temporary ASP.NET Files both in Framework and Framework64
• Redeploy site
• Repair installation of C++ Redistributable
• Reboot
• Start IIS

with no luck.

[Taritsyn]

Reinstall via NuGet.

[starteleport]

Finally figured it out. Started to work after I disabled Glimpse HTTP module. Very strange. Thanks, @Taritsyn!

[mynkow]

This error happens when you publish a website with MSBuild outside of VisualStudio. I am investigating if the nuget is built properly because these files are in Content folder.

[Section9Code]

I was having exactly the same problem. Worked fine locally, but on the server wasn't working at all. Installed the latest C++ Redistributable then an IIS reset solved the problem.

[Taritsyn]

... then an IIS reset solved the problem.

@Section9Code During publishing of native assemblies, you must always reset IIS. I recommend you to read the “File lock on LibSassHost.Native-64.dll” discussion.

[Taritsyn]

Hello!

Since version 1.2.6 the MSVC runtime was embedded into the native assemblies for Windows. Now you do not need to install the Microsoft Visual C++ Redistributable.