www programming

The fact that php is not allowed (someway into your configuration, but it is strange) to read the default /wp-w3all-phpbb-integration/addons/page-forum.php file? Did you removed this file into addons/ folder? If yes just re-download it if you want and put it into addons folder:
https://plugins.trac.wordpress.org/expo ... -forum.php

But this is not a problem. whatever you choose to do

the important is, that you setup the page name/slug (so forum or board or whatever)
into related admin plugin option
THEN, after it, if the file result not created or as you report it is an empty file
JUST
copy the default file /wp-w3all-phpbb-integration/addons/page-forum.php
and manually paste into your active template folder, renaming it as needed, so
page-board.php if board is the actual setting on related option, or leave as page-forum.php, if forum is your setting.
This is it

Thanks,

I shot myself in the foot. I had renamed page-forum.php while testing and never named it back. I am now able to create my page-xxxxx.php.

Back to working on the resizing issue. Everything works fine when screen is reduced, but forum isn't displaying when I'm in full screen. I will be trying your suggestions on this issue today.

Thanks again
John

I see the cause of my forum not being displayed at widths larger than 921px. Well, not sure if this statement is my issue, but my forum displays at 921px or less, but doesn't display at 922 or greater.

@media (max-width: 921px)

yes, if another element that wrap the div that wrap the iframe apply css rules causing this, you have to adapt the css to be different in the case of the page where it display.
So you could apply these edits into page-forum(orWhatEverNamed).php of your active template folder (or related awesome iframe shortcode file /wp-content/plugins/wp-w3all-phpbb-integration/common/wp_phpbb_iframe_shortcode.php ):

where there is this line add just after, so inside this css declaration that will be loaded when page will load, may adding !important to declarations, so that any other css that affect will be overwritten

Thanks,

I'm not an expert at CSS coding.

I see the statement in page-forum.php that seems to affect my issue. the width is being set to 1px (width:1px). This setting seems to take when I am in full screen mode. If i change that to 1000px the forum shows up in full screen mode

<div id="" class="">
<iframe id="w3all_phpbb_iframe" style="width:1px;min-width:100%;*width:100%;border:0;" scrolling="no" src="<?php echo $w3all_url_to_cms; ?>"></iframe>

Yes, may this will work better in any case, removing it? The way it is, was added long (years) time ago, to fix issues with safari, so that may it is time to review this inline css