I’ve only experienced this error when transferring databases from old WordPress installs on to new Plesk WordPress installs. After transferring the database, the homepage loads fine, but the rest of the site links produce a “Page not found” or a 404 error.
This is an easy fix, as you should still be able to reach your WordPress dashboard. Once there, all you have to do is go to Settings > Permalinks and Save without making any changes (technically just loading the page should do the trick).
Check to make sure this has fixed the issue, if not you may need to define you URL’s (something I may cover later).