Haswell drupal 8 theme installed but pages are not working

We have purchased haswell drupal theme. Installed both demo sql and drupal 8 fine, but none of the pages works except for the landing page.
Any idea of what we could have missed during our installation?

Object not found!

The requested URL was not found on this server. The link on the referring page seems to be wrong or outdated. Please inform the author of that page about the error.