Unable to load DLL 'NativeLibrary' _internal_decompress - LZDecompress

I have application written in C# and I want to load dll to uncompress LZC file. To do this I have code that call native method:

public static int Decompress(byte[] compressedData, byte[] decompressedData)
{
   return _internal_decompress(compressedData, compressedData.Length, decompressedData,
                decompressedData.Length);
}

But when application try to call _internal_decompress I get error:

System.DllNotFoundException: 'Unable to load DLL 'NativeLibrary': The specified module could not be found. (Exception from HRESULT: 0x8007007E)'