0 => Undefined array key "imageCount"
1 => Trying to access array offset on value of type null
  <div class="view auction ajax itemShowImages">
    <h2>
        <span class="bidNo">Rop 93</span>
        <span class="title">Ackumulatortank 500L</span>
    </h2>
    <div class="mediaContainer">
			<div class="tabs colored gray"><a class="tab selected" data-type="images">
    Bilder<span class="counter"></span>
  </a></div>
			
			<div class="tabContainer images"></div>
			<div class="tabContainer description"></div>
    </div>
  </div>
	<script>
		$(".mediaContainer .tabs .tab").click( function() {
			let tabType = $( this ).data( "type" );
			let containerClass = ".mediaContainer .tabContainer." + tabType;

			$(".mediaContainer .tabs .tab").removeClass( "selected" );
			$( this ).addClass( "selected" );

			$(".mediaContainer .tabContainer").hide();
			$( containerClass ).show();
		} );
	</script>