The Special:UserLogin/signup page is treating all the text in the MediaWiki:Shoutwiki-loginform-tos interface-page as simple text. IOW, no active links & therefore no tos document. I'm running MW 1.25.1
The Extension is no longer usable.
Topic on Extension talk:NewSignupPage
Every N months/years someone changes the core MediaWiki file includes/templates/Usercreate.php intentionally so that it breaks NewSignupPage. See r45820 for the original change that I committed years ago which is needed for NewSignupPage to function correctly, and gerrit:187479 for the most recent reversion of my changeset. At this point I've given up on getting the core stuff fixed — it's (unfortunately) easier to reapply the one-line patch than to constantly argue about that and why it's needed.