Event Organiser breaks the theme [closed]

Your events page has:

<div id="primary">
    <div id="content" role="main">
        <article id="post-4765" class="post-4765 event type-event status-publish hentry">
            <header class="entry-header">

Your home page has:

<div class="container_6">
    <div id="main" class="site-main clearfix">
        <div id="primary" class="content-area grid_4">
             <div id="content" class="site-content" role="main">
                 <article id="post-4684" class="post-4684 post type-post status-publish format-standard hentry category-discus tag-robert-harting">
                      <header class="entry-header">

To get consistent formatting you need consistent markup. You need to get those into alignment.

I think it is probably a straight HTML question at this point which makes it off-topic. How much of that code is generated by the plugin?