In checkout page loader stuck and spinning forever. There are no js errors in console. HTML of spinner looks like this

<div id="checkout-loader" data-role="checkout-loader" class="loading-mask" data-mage-init='{"checkoutLoader": {}}'>
    <div class="loader">
        <img src="<?php /* @escapeNotVerified */ echo $block->getViewFileUrl('images/loader-1.gif'); ?>"
             alt="<?php /* @escapeNotVerified */ echo __('Loading...'); ?>"
             style="position: absolute;">
    </div>
</div>

File checkout-loader.js looks like this

define([
'rjsResolver'
], function (resolver) {
'use strict';

/**
 * Removes provided loader element from DOM.
 *
 * @param {HTMLElement} $loader - Loader DOM element.
 */
function hideLoader($loader) {
    $loader.parentNode.removeChild($loader);
}

/**
 * Initializes assets loading process listener.
 *
 * @param {Object} config - Optional configuration
 * @param {HTMLElement} $loader - Loader DOM element.
 */
function init(config, $loader) {
    resolver(hideLoader.bind(null, $loader));
}

return init;
});

I tried console.log on init() function and it works, but not in hideLoader() function – so it is not called.

Also site using IWD_Opc extension.

Can you please give a hint where to look up the error

UPDATE

Here is some dirty fix that works for me.
I added line

resolver($loader.parentNode.removeChild($loader));

to init() function in checkout-loader.js

and line

$(document).find(blockLoaderClass).remove(); 

to removeBlockLoader() function in block-loader.js