Perch cannot publish a post 'Sorry, that post cannot be updated'

Perch cannot publish a post, it says 'Sorry, that post cannot be updated'.

The debug results in this in red:

0.0679  0.0003  Invalid query: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'postURL' in 'field list'

Is this a url issue in my template?

Diagnostic report:

Perch: 2.7.2, PHP: 5.5.15, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: bf9ad53b11c9a57efdb1057292d73b928b8c5c77 $, with PDO
Server OS: Linux, apache2handler
Installed apps: content (2.7.2), assets (2.7.2), categories (2.7.2), perch_blog (4.5.2), perch_mailchimp (2.0.1)
App runtimes: <?php include(PERCH_PATH.'/core/apps/content/runtime.php'); include(PERCH_PATH.'/addons/apps/perch_blog/runtime.php'); ?>
PERCH_LOGINPATH: /perch
PERCH_PATH: /home/hcih/public_html/perch
PERCH_CORE: /home/hcih/public_html/perch/core
PERCH_RESFILEPATH: /home/hcih/public_html/perch/resources
Image manipulation: GD
PHP limits: Max upload 2M, Max POST 8M, Memory: 32M, Total max file upload: 2M
Resource folder writeable: Yes
HTTP_HOST: www.hcih.co.uk
DOCUMENT_ROOT: /home/hcih/public_html
REQUEST_URI: /perch/core/settings/diagnostics/
SCRIPT_NAME: /perch/core/settings/diagnostics/index.php

Template:

<div class="blogpostt">
    <a href="<perch:blog id="postURL" />">
        <perch:blog id="postTitle" type="text" required="true" size="xl" label="Title" order="1" />
    </a>
</div>

<div class="blogposttime">
    <perch:blog id="postDateTime" type="date" time="true" label="Date" format="%d %B %Y" divider-before="Meta information" />
</div>
<div class="blogposttime">
    <perch:if exists="authorGivenName">by <perch:blog id="authorGivenName" type="hidden" /> <perch:blog id="authorFamilyName" type="hidden" /></perch:if>
</div>

<div class="blogposti">
    <perch:if exists="image">
        <div>
            <img src="<perch:blog id="image" type="image" width="850" height="450" crop="false" label="Image" order="4" />" alt="<perch:blog id="postTitle" />" />
        </div>
    </perch:if>
</div>

<div class="blogpostp">
    <perch:blog id="postDescHTML" type="textarea" label="Post" editor="redactor" html="true" size="xxl" order="2" required="true" />
</div>

<perch:categories id="categories" set="blog" label="Categories" display-as="checkboxes">
    <a href="archive.php?cat=<perch:category id="catSlug" type="slug" />">
        <perch:category id="catTitle" type="text" />
    </a>
</perch:categories>

<perch:blog id="image" type="image" width="50" height="50" crop="true" suppress="true" />