installation canary Error Message upon installation
The message itself gives a quite bit of info that the installation wasn't done correctly or there would be something missing from the process. Make sure you followed the docs correctly while installing CiviCRM.

I've seen this on doing a page relaod while the installation is still in progress.

If you think the process is done correctly and just want to get rid if this error - try deleting civicrm_install_canary table from the database and reload the page.