If I try and edit a post from my wp-admin dashboard, I get a “Page Not Found” error.I have tried many different things and I can’t access any of the dashboard options. I would like to reset the permalinks but again I get a page not found message. I can access the Plugin page but I have deactivated all the plugins and still the same thing. Any help is appreciated.
Delete the root .htaccess file and try again.
You could try downloading latest WordPress and overwrite the entire /wp-admin folder. Could be missing a file.
Make a backup first.