Did you install other plugins and/or templates? Which?
You installed this on a NAS. What is the webserver you are using? Apache?
Could you check the logs of the webserver? Are there any messages?
could you check the JavaScript console in the browser? Are there messages?
Just to be sure, could you refresh your browser with Crtl+R or Ctrl+F5? (It should not do much, but for some cases this skips some browser caches.