First of all, I have no experience with PHP, so anything I say or do in that direction can be utterly wrong. Don't do anything written in this post on your live install. I had the problem and error described here: http://xenforo.com/community/threads/8wayrun-com-xenporta-portal.26838/page-37#post-369340 On my local install (also php 5.4) I found the same error on the same spot in the XenPorta application. I fiddled around, and did something (in the "lol I've no idea what I'm doing" fashion) and to my surprise it worked. (EDIT: To be clear, server is running linux, the local install is running on windows. Both use nginx, and have the same config for nginx, php-fpm and mysql.) In Node.php I looked up line 1255 and changed the following: Code: 'selected' => (strval($selectedNodeId) === '0'), To Code: 'selected' => ($selectedNodeId), And to my surprise the page loaded without the error that had come first. I have no idea what security issues this induces, so I think it's best for some professionals to look at it. My apologies if this isn't a bug, and I suggest for other people to NOT change this in their install. On another server I had a couple applications breaking because PHP handles things different in their newest version. Perhaps (what I've seen with other applications) is something between the lines of if php is lower than version 5.4 do this, else do that. Also my apologies if this all seems a bit unclear and confusing, I've been trying to get things to work all day, and am tired now. I hope anybody can help me, and many thanks in advance!