EBUSY error when deleting a file using unlink

I have a delete route which deletes an image file. Following is the code:

router.delete('/:id', (req, res) => {
    let pathForThumb = '';
    let pathForImage = '';

    Image.findOne({ _id: req.params.id })
        .then(getImage => {
            pathForThumb = getImage.thumbPath;
            pathForImage = getImage.imagePath;
            getImage.remove();

        })
        .then(removeThumb => {
            fs.unlink(pathForThumb, (err) => {
                if (err) {
                    req.flash('error_msg', 'There was an error deleting the thumbnail');
                    res.redirect('/user/userdashboard');
                }
            });
        })
        .then(removeMainImage => {
            fs.unlink(pathForImage, (err) => {
                if (err) {
                    console.log(err);
                    req.flash('error_msg', 'There was an error deleting the main image');
                    res.redirect('/user/userdashboard');
                } else {
                    req.flash('success_msg', 'Image removed');
                    res.redirect('/user/userdashboard');
                }
            });

        })
        .catch(err => {
            console.log(err);
        });
});

as you can see when I upload a file I store it's path and also generate a thumbnail in the /uploads/thumbs/ folder and store the path of the thumb nail as well. In the above code I first get the image using findOne, store the paths of both images in variables and then call fs.unlink in a promise. What is happening is that my thumbnail gets deleted but I am getting the following error in the removeMainImage then condition:

{ Error: EBUSY: resource busy or locked, unlink 'C:\Users\Amin Baig\Desktop\Teaching\galleryprj\public\uploads\XC6kPqWf9_dphaBmUG__I7SN7PAEl_1531823330941_CEI21.jpg'
  errno: -4082,
  code: 'EBUSY',
  syscall: 'unlink',
  path: 'C:\\Users\\Amin Baig\\Desktop\\Teaching\\galleryprj\\public\\uploads\\XC6kPqWf9_dphaBmUG__I7SN7PAEl_1531823330941_CEI21.jpg' }

I am using windows 10 for my dev environment os. Have been trying to find a solution for this, please help.