Instead of an indexmenu , you are getting these:
search?q=%3A&btnI=lucky
search?q=%3Ascrapbook&btnI=lucky
search?q=.&btnI=lucky
this happens when the indexmenu plugin is not installed. It mistakes the indexmenu syntax for an interwiki link, probably because of the
> character occuring in a link syntax. So, for instance, if you enter the following syntax into a page
{{go>austen}}
you get a corrupted interwiki link to a google search for jane austen:
search?q=austen&btnI=lucky
Either the indexmenu plugin is not installed, or if installed disabled or corrupt. I don't think it's the result of a plugin conflict, but I could be wrong.