Perch Blog 5.0 - Fatal Error after installation

Diag report as follows:

PERCH INFORMATION

Perch: 2.8.15
Production mode: Production (100)
Installed apps: content (2.8.15), assets (2.8.15), categories (2.8.15), perch_blog (5.0)
DB driver: PDO
DB tables: perch2_blog_authors, perch2_blog_comments, perch2_blog_index, perch2_blog_posts, perch2_blog_posts_to_tags, perch2_blog_sections, perch2_blog_tags, perch2_categories, perch2_category_counts, perch2_category_sets, perch2_content_index, perch2_content_items, perch2_content_regions, perch2_navigation, perch2_navigation_pages, perch2_page_templates, perch2_pages, perch2_resource_log, perch2_resource_tags, perch2_resources, perch2_resources_to_tags, perch2_settings, perch2_user_privileges, perch2_user_role_privileges, perch2_user_roles, perch2_users
Users: 2
App runtimes:
<?php
    $apps_list = array(
        'content', 
        'categories',
        'perch_blog',
    );
?>
Scheduled tasks for perch_blog: delete_spam_comments (1440 mins)
Editor plug-ins: ckeditor, markitup
H1: 1b2892007ca8c60f4e162f304fd27831
L1: fffb6a681a281b0ae6887f514168c635
headerColour: #515151
content_singlePageEdit: 1
helpURL:
siteURL: /
hideBranding: 1
content_collapseList: 1
lang: en-gb
update_2.8.2: done
latest_version: 2.8.15
on_sale_version: 2.8.15
headerScheme: dark
dashboard: 1
hide_pwd_reset: 0
content_hideNonEditableRegions: 0
content_frontend_edit: 0
update_2.8.3: done
perch_blog_post_url: /blog/post.php?s={postSlug}
perch_blog_slug_format: %Y-%m-%d-{postTitle}
perch_blog_akismet_key:
perch_blog_max_spam_days: 0
perch_blog_comment_notify: 0
logoPath:
perch_blog_update: 5.0.1
update_2.8.15: done
perch_blog_site_name: xxxxxx
PERCH_DEVELOPMENT: 10
PERCH_STAGING: 50
PERCH_PRODUCTION: 100
PERCH_DB_USERNAME: xxxxxx_cms
PERCH_DB_SERVER: 10.168.1.92
PERCH_DB_DATABASE: xxxxx_cms
PERCH_DB_PREFIX: perch2_
PERCH_TZ: UTC
PERCH_EMAIL_FROM: xxxx
PERCH_EMAIL_FROM_NAME: xxxx
PERCH_LOGINPATH: /xxxxxx
PERCH_PATH: /var/sites/a/xxxxxx/public_html/xxxx
PERCH_CORE: /var/sites/a/xxxxxx/public_html/xxxx/core
PERCH_RESFILEPATH: /var/sites/a/xxxxxxx/public_html/xxxxx/resources
PERCH_RESPATH: /xxxxxx/resources
PERCH_HTML5: 1
PERCH_RUNWAY:
PERCH_ERROR_MODE: DIE
PERCH_DATE_LONG: %d %B %Y
PERCH_DATE_SHORT: %d %b %Y
PERCH_TIME_SHORT: %H:%M
PERCH_TIME_LONG: %H:%M:%S
PERCH_DEBUG:
PERCH_PREVIEW_ARG: preview
PERCH_TEMPLATE_PATH: /var/sites/a/xxxxxx/public_html/xxxxxx/templates
PERCH_DEFAULT_DOC: index.php
PERCH_DEFAULT_EXT: .php
PERCH_PRODUCTION_MODE: 100
PERCH_RWD:
PERCH_HTML_ENTITIES:
PERCH_SSL:
PERCH_STRIPSLASHES:
PERCH_PROGRESSIVE_FLUSH: 1
PERCH_AUTH_PLUGIN:
PERCH_DB_CHARSET: utf8
PERCH_DB_PORT:
PERCH_DB_SOCKET:
PERCH_SESSION_TIMEOUT_MINS: 20
HOSTING SETTINGS

PHP: 5.5.26
Zend: 2.5.0
OS: Linux
SAPI: cgi-fcgi
Safe mode: not detected
MySQL client: mysqlnd 5.0.11-dev - 20120503 - $Id: 15d5c781cfcad91193dceae1d2cdd127674ddb3e $
MySQL server: 5.6.21
Extensions: Core, date, ereg, libxml, openssl, pcre, sqlite3, zlib, bcmath, calendar, ctype, curl, dom, hash, fileinfo, filter, ftp, gd, gettext, SPL, iconv, session, json, ldap, mbstring, mcrypt, mssql, standard, mysql, mysqlnd, mysqli, PDO, pdo_mysql, pdo_pgsql, pdo_sqlite, pgsql, Phar, posix, Reflection, imap, SimpleXML, soap, sockets, exif, tidy, tokenizer, xml, xmlreader, xmlrpc, xmlwriter, xsl, zip, cgi-fcgi, memcache, geoip, mhash, ionCube Loader
GD: Yes
ImageMagick: No
PHP max upload size: 100M
PHP max form post size: 100M
PHP memory limit: 128M
Total max uploadable file size: 100M
Resource folder writeable: Yes
Session timeout: 240 minutes
Native JSON: Yes
Filter functions: Yes
Transliteration functions: No
DOCUMENT_ROOT: /var/sites/a/xxxxxxx/public_html
GATEWAY_INTERFACE: CGI/1.1
HTTP_ACCEPT: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
HTTP_ACCEPT_ENCODING: gzip, deflate, sdch
HTTP_ACCEPT_LANGUAGE: en-US,en;q=0.8
HTTP_CONNECTION: close
HTTP_COOKIE: phpbb3_3lkb3_u=1; phpbb3_3lkb3_k=; phpbb3_3lkb3_sid=aa1f444d910829c3924e586c0ac7404d; phpbb3_g26k7_u=2; phpbb3_g26k7_k=; phpbb3_g26k7_sid=bdc09ad47b835e59745c8e5ec031f8bb; __utma=108869074.1260398506.1444165947.1447289315.1447294002.8; __utmc=108869074; __utmz=108869074.1444165947.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); __atuvc=0%7C41%2C17%7C42%2C0%7C43%2C8%7C44%2C8%7C45; cmsa=1; PHPSESSID=64516a215d473c23bde73a54801badac
HTTP_HOST: xxxxxx
HTTP_REFERER: https://xxxxxxx/xxxxxxx/core/settings/diagnostics/
HTTP_UPGRADE_INSECURE_REQUESTS: 1
HTTP_USER_AGENT: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36
HTTP_X_FORWARDED_FOR: 82.3.209.205
PATH: /bin
QUERY_STRING: extended
REDIRECT_STATUS: 200
REMOTE_ADDR: 82.3.209.205
REMOTE_PORT: 6189
REQUEST_METHOD: GET
REQUEST_URI: /xxxxx/core/settings/diagnostics/?extended
SCRIPT_FILENAME: /var/sites/a/xxxxxxxx/public_html/xxxxxx/core/settings/diagnostics/index.php
SCRIPT_NAME: /xxxxxx/core/settings/diagnostics/index.php
SERVER_ADDR: 10.168.1.228
SERVER_ADMIN: you@example.com
SERVER_NAME: xxxxxxxx
SERVER_PORT: 80
SERVER_PROTOCOL: HTTP/1.1
SERVER_SOFTWARE: Apache
PHP_SELF: /xxxxxxxx/core/settings/diagnostics/index.php
REQUEST_TIME_FLOAT: 1447454927.35
REQUEST_TIME: 1447454927
argc: 1

It's the default blog post template - whilst the app was installed in the CMS previously it was something never setup for the client

I was upgrading from Perch 2.8.3 an Blog 4.6

<article class="h-entry">
    <h1>
        <a href="<perch:blog id="postURL" type="hidden" />" rel="bookmark" class="p-name">
            <perch:blog id="postTitle" type="text" label="Title" required="true" size="xl autowidth" order="1" />
        </a>
    </h1>
    <p class="meta">
        <time class="dt-published" datetime="<perch:blog id="postDateTime" type="date" label="Date" time="true" format="Y-m-d H:i:s" divider-before="Publishing" />">
            <perch:blog id="postDateTime" type="date" time="true" format="%d %B %Y" /> 
        </time>
        <perch:if exists="authorGivenName">
            by <span class="p-author h-card"><perch:blog id="authorGivenName" type="hidden" /> <perch:blog id="authorFamilyName" type="hidden" /></span>
        </perch:if>    
        <perch:categories id="categories" set="blog" label="Categories" display-as="checkboxes">
            <a href="archive.php?cat=<perch:category id="catSlug" type="slug" />" class="p-category">
                <perch:category id="catTitle" type="text" />
            </a>
        </perch:categories>

    </p>
    <perch:if exists="image">
        <div>
            <img src="<perch:blog id="image" type="image" width="320" height="240" crop="true" label="Image" order="4" />" alt="<perch:blog id="postTitle" />" />
        </div>
    </perch:if>
    <div class="description e-content">
        <perch:blog id="postDescHTML" type="textarea" label="Post" order="2" editor="markitup" markdown="true" size="xxl autowidth" required="true" />
    </div>
</article>

<perch:blog id="excerpt" type="textarea" label="Excerpt" markdown="true" order="3" suppress="true" size="s" />
<perch:blog id="image" type="image" width="50" height="50" crop="true" suppress="true" />

Ok, just tried that but it still returns the same error

There were no posts as the blog hadn't been used.

However, I have since corrected the issue by deleting the perch_blog tables in the database and perch_blog_update record in the perch_settings table, logged back into Perch and the error is no longer showing. So something must have gone wrong during the db update initially.