Ah.... I got this when trying vault/install/index.php
My PHP version is 5.4.29
What should I do ah@@

You might have PHP 5.4.29 installed on your server as you say, but apparently your server also has PHP < 5.3 installed, and it is using that instead for vBulletin. You will have to make sure in your Apache, nginx, or other config, that it is using the correct path to the PHP 5.4.29 binary when a .php request comes in.

If you maintain multiple versions of PHP, it is usually easier to keep track of this if the PHP path has the version number in it. But I have found that it is sometimes possible to update the wrong PHP location if you forget to set your prefixes properly when you compile the update.

If this error did not occur, then the loaded page should tell you that the PHP version is too low, and the actual PHP version that is executing the page. You can try to get at least that far, so it can give you some clues about your version, by editing vault/core/model/vw.php. Find:
Replace with:

Thank you so much for your professional help, I'll try these code first and contact my site hoster if necessary. All the best!

The Gamma 7 version of VaultWiki Lite has been posted today, above. Here are some details of the release:

(released July 1, 2014)

• HTML5 MicroData in Wiki Pages
• vw_additional.css for easier CSS overrides
• Opt Wiki Areas In/Out of Web Search Results
• Improved CSS caching
• CSS separated into multiple templates for easier management
• fatal error searching wiki content in vB3
• word wrap occurs in CODE blocks
• word wrap is not multi-byte safe
• About 25 other bugs that weren't limited to vBulletin are fixed

Getting this error when installing:

Fatal error: Configuration: You must insert a value for dirs.core in /vault/core.php in /home/uta/public_html/forum/vault/core/model/vw.php on line 109

Looked and there is no core.php in my vault folder.

Nevermind, I was running PHP 5.2. Updated and looks to be working correctly now.

Running PHP 5.4 currently.

VaultWiki has been installed. I have yet to do any post installation configuration though. It seems when the VaultWiki plugin is enabled on my forums, suddenly BBCode does not display correctly on the forums. It just shows the tags around the text.

I disable VaultWiki, and suddenly BBCode parses correctly.

Screenshot of example of what I mean attached.

I cannot reproduce the problem on my Lite wiki. If you can, I would advise you to submit a Support Ticket through the Members area at vaultwiki.org, so that a developer can resolve this for you.

The error message refers to an incorrect file name, but the message means that VaultWiki is having trouble automatically finding your vBulletin root directory.

If you had some sort of open_basedir restriction which jails PHP to the vBulletin directory, this would be confusing to VaultWiki. However, from the error message, I don't see such a restriction.

If you have a Windows server with PHP 5.2.4 - 5.2.6 installed, the behavior of the PHP function realpath is inconsistent in this environment. In all PHP versions below 5.3.0, realpath randomly fails to return a value, and in 5.3.1, it only works in some cases.

I have logged a bug report at vaultwiki.org so that the developers can implement a workaround for these versions. Even if your PHP version is too low, VaultWiki is supposed to load far enough to tell you "your PHP version is too low"...

Release Candidate 1 has been posted today. Here are some of the changes in this release:
(released July 28, 2014)

• History updated: more detailed and user-friendly
• Fixed setting rebuilds in Debug Mode
• Fixed fatal error subscribing via tab
• Fixed sample area being invisible
• Fixed signatures failing to parse
• Fixed database error previewing new pages
• About 35 other bugs that weren't limited to vBulletin are fixed