Custom DLLs not loading in Azure? Might be a PATH issue… Here’s a fix.

Posted: September 25, 2015 in Azure, Microsoft, Programming, Software Development
Tags: , , , , , , , , ,

I recently ran into a need to use the LAME MP3 encoder in a customer’s website. Problem was, once I deployed to Azure, I received an error of “Unable to load DLL libmp3lame.32.dll”. Uh oh! “But it’s in the bin folder!” I screamed silently at Starbucks. So, I binged the issue and found a good answer on StackOverflow. I’m sharing here because it helped unstick me, and I imagine others may be running to this issue with libraries other than LAME.

I ended up adding the function to my Global.asax, in addition to importing namespaces System.IO and System.Linq:

/// <summary>
/// Updates PATH variable in hosting instance to allow referring to items in this project's /bin folder.
/// Very helpful with Azure.
/// </summary>
public static void CheckAddBinPath()
{
    // find path to 'bin' folder
    var binPath = Path.Combine(new string[] { AppDomain.CurrentDomain.BaseDirectory, "bin" });
    // get current search path from environment
    var path = Environment.GetEnvironmentVariable("PATH") ?? "";
 
    // add 'bin' folder to search path if not already present
    if (!path.Split(Path.PathSeparator).Contains(binPath, StringComparer.CurrentCultureIgnoreCase))
    {
        path = string.Join(Path.PathSeparator.ToString(), new string[] { path, binPath });
        Environment.SetEnvironmentVariable("PATH", path);
    }
}

Then in Application start I simply added:

// Sometimes files aren't loaded properly from bin. Hint to the app to load from /bin, too.
CheckAddBinPath();

I hope that helps!

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