Ошибка при добавлении в корзину

<section class="select msearch2" id="mse2_mfilter">
    <div class="select__img-wrap"></div>
    <div class="select__filter-wrap">
        <h2 class="select__title">Подбираем технику</h2>
        <p class="select__text">
            Воспользуйтесь нашим калькулятором для удобного поиска необходимой техники
        </p>
        <div class="select__filter">
            <form action="{$_modx->resource.id | url}" method="post" id="mse2_filters">  
                {$filters}
                <div class="select__search" id="reset-podbor" >
                    <button type="reset" class="btn btn--white">Сбросить</button>
    			</div>
            </form>
        </div>
    </div>
    <div id="mse2_results" class="select__filter-results product"  style="display:none;">
        {$results}
    </div>
    <div class="select__view-all" id="all" style="display:none;">
        <a href="{$_modx->makeUrl(5)}" class="btn btn--white" id="go">Посмотреть все</a>
    </div>
</section>

<div class="product__item ms2_product">
    <div class="product__img-wrap">
        <a href="{$id | url}"> 
            {if $popular?}
                <span class="product-equip__img-discount-icon">%</span>
                {*{$weight > '0' ? '<span class="badge-offer">{$weight} %</span>' : ''}*}
            {/if}
            <div class="product__badge">
                {if $new?}
                    <span class="product__img-under-the-order-icon">Новинка</span>
                {/if}
                {if $favorite?}
                    <span class="product__img-under-the-order-icon">Хит продаж</span>
                {/if}
                {if $postav_count == 0 AND $osn_count == 0 AND $jelezo_count == 0}
                    <span class="product__img-under-the-order-icon">Под заказ</span>
                {/if}
            </div>
            {if $thumb?}
                <img src="{$small}" alt="{$pagetitle}" class="product__img">
            {else}
                <img src="assets/templates/img/sprites/sprite-logo.svg#logo-header" alt="{$pagetitle}"/>
            {/if}
            {if $youtube_video?}
                <a data-fancybox href="https://www.youtube.com/watch?v={$youtube_video}" class="link-img">
                     <span class="product__img-video-icon"></span>
                </a>
            {/if}
        </a>
    </div>
    <form action="" method="post" class="ms2_form">
        <input type="hidden" name="id" value="{$id}">
        <input type="hidden" name="count" value="1">
        <input type="hidden" name="options" value="[]">    
        <h2 class="product__title">
          {$pagetitle|replace:",":", "}
        </h2>
        <ul class="product__desc">
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Мощность двигателя:</span>
                    <span class="product__desc-charact">{$_pls['cubature.value']} см3</span>
                </li>
            {/if}
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Размер колес:</span>
                    <span class="product__desc-charact">{$_pls['wheelsize.value']} см3</span>
                </li>
            {/if}
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Коробка передач:</span>
                    <span class="product__desc-charact">{$_pls['transmission.value']} см3</span>
                </li>
            {/if}
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Рост:</span>
                    <span class="product__desc-charact">{$_pls['growth.value']} см3</span>
                </li>
            {/if}
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Возраст:</span>
                    <span class="product__desc-charact">{$_pls['age.value']} см3</span>
                </li>
            {/if}
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Стартер:</span>
                    <span class="product__desc-charact">{$_pls['starter.value']} см3</span>
                </li>
            {/if}
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Фара:</span>
                    <span class="product__desc-charact">{$_pls['headlight.value']} см3</span>
                </li>
            {/if}
            {if $_pls['cubature.value']?}
                <li class="product__desc-point">
                    <span class="product__desc-name">Тип двигателя:</span>
                    <span class="product__desc-charact">{$_pls['enginetype.value']} см3</span>
                </li>
            {/if}
        </ul>
        <span class="product__price">{$price} ₽</span>
        {if $old_price !== '0'}
            <span class="product__old_price">{$old_price} ₽</span>
        {/if}
        <div class="moto__btn-group">
            <button type="submit" name="ms2_action" value="cart/add" class="moto__btn btn btn--white moto__btn--cart">
              <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
                <use xlink:href="assets/templates/img/sprites/sprite-header-icons.svg#cart"></use>
              </svg>
            </button>
            <a href="{$id | url}" class="btn moto__btn--more">
                Подробнее
            </a>
        </div>
    </form>
  </div>