Do you use the latest version of the theme? Do you have a child theme?
Go to Settings > Permalinks > check if you use the Post name type http://prntscr.com/s7zqco and re-save permalinks. If “Post name” is selected already, select another one, then set “Post name” and save.
Let us know the result.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.