I have just upgraded to 5.23.1 from 5.15.2 (Drupal 7.69) The upgrade screen was a bit "mumbled" but I assumed it worked ok. When I went back in to Civicrm I first get a message:
Sorry, due to an error, we are unable to fulfill your request at the moment. You may want to contact your administrator or service provider with more details about what action you were performing when this occurred. DB Error: no such field Return to home page.<<
When I return to home page and click on my record I can see it in Civicrm but there are no menus and I cannot see anyone else or anything else.