File Failing to copy to another directory (fs.access and copyFile)

I'm trying to copy pdf and/or word documents from one folder into another. The code below works sometimes, but then other times it does not.

app.post('/api/file_archive/:file_name', function (req, res) {
    var file_name = req.params.file_name;
    var src = 'public/uploads/files' + file_name;
    var dest = 'archived_files/files';

    if(file_name != "") {
        console.log("Entered fs access");
        fs.access(dest, function(err) {
            if(err)
                fs.mkdirSync(dest);

            copyFile(src, path.join(dest, file_name));
            res.json({ message: 'file archived!'});


        });
    };
});

I'm currently receiving this error:

{ Error: ENOENT: no such file or directory, open 'C:\Users\duquetr\Documents\maize-and-blue-brief\public\uploads\files\1495121011192_Letter of Rec for RJ.pdf' at Error (native) errno: -4058, code: 'ENOENT', syscall: 'open', path: 'C:\\Users\\duquetr\\Documents\\maize-and-blue-brief\\public\\uploads\\files\\1495121011192_Letter of Rec for RJ.pdf' }

I've searched around a bit and I can't seem to find anything that pertains to why this code sometimes works.

Thanks for your help!

via Ronald Duquette