following code will throw out Exception like this using LINUX. Using Windows, everything is all right, but code will be hosted under LINUX, so it can't be hosted, actually. Exception:
Unknown Property – yii\base\UnknownPropertyException
Setting unknown property: kartik\checkbox\CheckboxX::autoLabel
Code, which will run under Windows, but not under LINUX:
<div class="col-md-3">
<?=$form->field($model, 'veroeffentlichen_bewerberboerse')->widget(\kartik\checkbox\CheckboxX::classname(), ['autoLabel' => true])->label(false);
?>
</div>