Error: Unable to load DLL '.dll' : The specified module could not be found. (Exception from HRESULT: 0x8007007E) - What is this error?

Question

The Situation:

I'm trying to run CharLS JPEG-LS Compression algorithm implementation

There is source code in the site about where you can download a C# VS 2010 Solution. In the Solution there are, 2 C# Class Library Projects, 1 Unmanaged VC++ project and 1 C# Console App. The console App calls one of the class libraries, `using CharLS;', and that particular library references the unmanaged VC++ project. The console application works perfectly on debug mode.

The Problem:

But when I compiled the console app for "Release", and ran the .exe (executable file), when a particular function is called during the process, it gives me this error:

Error: Unable to load DLL 'CharLS.dll' : The specified module could not be found. (Exception from HRESULT: 0x8007007E)

I've also tried to create another project and reference the class library from there, but I get the same error.

I've tried reading other solutions for this over the net but they have not helped me.

Solution

Some of the reasons for this error could be:

1. the name you are providing to the "EntryPoint" property of "DllImport" attribute is not matching with the function you are exporting from the native component.

2. Another reason could be missing dll itself/or any of its dependencies(use dependency walker and check)

3. Third reason could be it could be debug/release version mismatch.

Comments

[user919789]

I've tried (re-)building countless times already. Same error sir.

[Seph]

@user919789 did you try a clean and rebuild of the whole solution in combination with closing and re-opening visual studio? It usually fixes the error for me.

[Avi Turner]

Kudos (and +1) for the debug/release version mismatch. I was testing a project deployment and did not bother to switch solution configuration to "Release".