Search Page not working

HI! I got a job to fix the search page in a blog (http://www.docol.com.br/planetaagua/), but everything i tried not worked at all 🙁
the search page displayed after a search is blank! as you can see by this link: http://www.docol.com.br/planetaagua/?s=test
I dunno what to do! Do you guys have any tips?