select2 "required problem" solution

select2.html

<div class="select2-wrapper">
    <select required>
        ...
    </select>
</div>

<style>
    .select2-offscreen,
    .select2-offscreen:focus {
        clip: rect(0 0 0 0) !important;
    /*    The message is squashed and not seen.*/
    /*    width: 1px !important;*/
    /*    height: 1px !important;*/
        border: 0 !important;
        margin: 0 !important;
        padding: 0 !important;
        overflow: hidden !important;
        position: absolute !important;
        outline: 0 !important;
        left: 0px !important;
        top: 0px !important;
    }
    .select2-wrapper {
        position: relative;
    }
</style>