Unhandled Error!

    <div class="hero banner">
        <div class="container">
            <div class="row">
                <div class="col-sm-24 col-md-20 col-md-offset-2">
                    <div class="content">
						<span class="snippet">News</span>
                        <h1 class="title"><?= $post->title; ?></h1>
						<div class="author">
							<? $user_image = Users_User::create()->find($post->created_user_id); ?>
							<div class="author-picture">
								<img src="<?= $user_image->photo->getThumbnailPath(150, 'auto'); ?>" alt="<?= $post->author_first_name; ?> <?= $post->author_last_name; ?>" />
							</div>
							<span>by <?= $post->author_first_name; ?> <?= $post->author_last_name; ?> on <?= $post->published_date->format('%e %B %Y'); ?></span>