Upgrade to 8.4.5 failed

I upgraded my site in the usual manner:

~/drupal-8.5.0$ cp -R core ../
~/drupal-8.5.0$ cp -R vendor ../
~/drupal-8.5.0$ cp *.php ../
~/drupal-8.5.0$ cp *.json ../
~/drupal-8.5.0$ cp *.config ../

But then get a “server encountered an unexpected error message. I tried it twice with the same results.

I am on a hosted server and cannot use composer or drush alas. What could be wrong?

Thanks in advance for any help

Drupal version: 

Source: https://www.drupal.org/taxonomy/term/21/feed