Issue installing Wiki for Vbulletin 4

Dear Support,

I'm after installing vaultwiki and when I go to the homepage I get the following error

--------------
Only admins can see this error. Other users can visit the site normally, but your immediate attention is needed in the AdminCP.

Invalid default namespace ID detected. Make sure that you have set up the default namespace via the Namespace Manager. If you have, it is possible that the Namespace Cache is not up to date because of a recent change or VaultWiki upgrade. To solve this issue, simply go to the Namespace Manager and select [Rebuild All Namespaces].

If you still receive this error after rebuilding namespaces, contact VaultWiki support.
IPIC (Irish Paranormal Investigation Crew) Forum
--------------

I've run the rebuild but still get the message. Any help you can provide will be helpful.

Kindest Regards
Garret

Did you create your first wiki forum yet? https://www.vaultwiki.org/manual/Initial-Setup