Seems as if you have deleted
<div class="container"> from your header.php</div>
Hi LB, in addition to the helpful tips above, the appropriate support forum for this theme can be found here.
Or, you can interact directly with the author here. The link takes you to the item’s Comments section, where you can also browse previous posts for additional information and/or troubleshooting.
Just leave the author a quick comment and he’ll gladly point you in the right direction. Good luck.
Go to WordPress admin – Appearance – Editor
On the right side, select header.phpBelow this:
< body >add this:
<div id="container"> </div>