After update WP will not save any changes in Dashboard

After I updated using the update automatically and then again with reinstall automatically, I cannot make any changes in the dashboard. I’ve tried editing stylesheet.css and when I click “update file” the browser directs me out of the dashboard and to the actual blog. Same thing happens when I tried to deactivate plugins. I’ve also tried to change themes, however, it will not accept any changes.

Any suggestions would be appreciated