If you are using WCM siteadmin and wish to create a new page/site using the available buttons, they may appear disabled so that you are unable to click on them. Firstly, you should check your permissions for these actions and/or check with an administrator or admin account. If these problems persist it may be related to an issue in your repository structure.
These buttons can also be disabled if there is an invalid Page node in the /content tree. A cq:Page node must have a child named jcr:content of type cq:PageContent, otherwise it is invalid and can lead to this issue. The root /content node is not of type cq:Page and therefore does not require a jcr:content child of type cq:PageContent, but every other Page node below /content should have this structure.
It seems that if the invalid node is a top-level page/site in the content tree (e.g. /content/geometrixx) then it will affect the site actions for all other top-level nodes, and other nodes in that specific tree.
If the invalid node is a sub node (e.g. /content/geometrixx/en/services), then it seems to only affect the site actions for that level in that tree.
Such invalid nodes can appear in the tree if they were created outside of WCM (i.e. using CRXDE, or Content Explorer), or by importing a package containing such invalid nodes.
Check your content tree for such invalid page nodes, and repair the nodes as required, by creating a jcr:content child node of type cq:PageContent.