Install Issue : PP 5.11 + PHP-Nuke Platinum 7.6.0

[VSDan]

Software
===================
- PHP-Nuke Platinum 7.6.0
- PhotoPost 5.11


Background
===================
Initially installed PhotoPost, integrated with phpBB (as part of PHP-Nuke). Made an error with regard to table prefix during configuration, and decided to integrate with PHP-Nuke directly. Via phpMyAdmin, deleted newly created PhotoPost tables, and reinstalled. This resulted in the following issues - see next section.


Issues
===================
1. Not logged in:
- can access forums, but cannot post [OK]
- can access gallery, but cannot view [OK]

2. Logged in as ADMIN:
- can access forums, but cannot post [OK]
- can access gallery, but cannot view [OK]
- can logout via PHP-Nuke Admin [OK]

3. Logged in as USER (via PHP-Nuke):
- cannot access forums (get 500 error that is not logged by server - seems to be local error) [FAIL]
- can access gallery, but cannot view [FAIL]

(a) While still logged in to PHP-Nuke, login via PhotoPost:
- can access gallery, and view [OK]
- cannot access forums (get 500 error that is not logged by server - seems to be local error) [FAIL]
- cannot logout via PhotoPost [FAIL]
- cannot logout via PHP-Nuke (can still access user functions in PHP-Nuke and view gallery)[FAIL]

(b) Not logged in via PHP-Nuke, login only via PhotoPost:
- can access gallery, and view [OK]
- cannot access forums (get 500 error that is not logged by server - seems to be local error) [FAIL]
- cannot logout via PhotoPost [FAIL]
- cannot logout via PHP-Nuke (can still access user functions in PHP-Nuke and view gallery)[FAIL]

Appears to be cookie-related issue, but unsure as to how to resolve. But why cannot access forums when I clear all cookies (including PhotoPost cookies), close and open new browser, and only login via PHP-Nuke (PhotoPost not involved)? This issue only began after the PhotoPost install - not sure if after 1st or 2nd install.

[VSDan]

Added Note
===============

If I comment out the following line in the Forums/index.php file:

$template->pparse('body');
(->parser function in inclcudes/template.php file)

...then Forums will load, but missing middle body portion containing forum categories. However, all other links work - including search, which also use $template->pparse('body');. Issue is further isolated, and isolated to index.php.