Why can't I use a theme other than Dawn?

[p-pym]

I tried changing the theme of my store from Dawn to Sense or any other theme but I couldn't. When I switch to other themes Every page of my website will have "null" on every page. How can I fix this?

[EcomGraduates1]

Unfortunately those two  are different themes  and you cannot  go into the settings schema  and  and copy and paste  
you can download sense  free theme and design it  even bettter than dawn theme  but you cant "transfer" the  layout or copy of it