Grafana Browser Error

I had grafana 7.1.0 but now i was installing 6.2 version.after installing both are not working.I have getting below error
If you’re seeing this Grafana has failed to load its application files

  1. This could be caused by your reverse proxy settings.
  2. If you host grafana under subpath make sure your grafana.ini root_url setting includes subpath
  3. If you have a local dev build make sure you build frontend using: yarn start, yarn start:hot, or yarn build
  4. Sometimes restarting grafana-server can help