Crash and site down upgrading from 8.5.6 to 8.6.0

I was trying to update my drupal… and got the next message:

drush up drupal
Update information last refreshed: Jue, 06/09/2018 - 21:56
Name   Installed Version Proposed version Message
Drupal 8.5.6             8.6.0            Actualización disponible

Code updates will be made to drupal core.
WARNING: Updating core will discard any modifications made to Drupal core files, most noteworthy among these are .htaccess and robots.txt. If you have made any modifications to these files, please back them up before updating so that you can re-create your modifications in the updated version of the file.
Note: Updating core can potentially break your site. It is NOT recommended to update production sites without prior testing.

Do you really want to continue? (y/n): y
PHP Fatal error: Method DrupalCoreStringTranslationTranslatableMarkup::__toString() must not throw an exception, caught Error: Class 'DrupallocaleSourceString' not found in phar:///usr/local/bin/drush/includes/output.inc on line 0
PHP Fatal error: Method DrupalCoreStringTranslationTranslatableMarkup::__toString() must not throw an exception, caught Error: Class 'DrupallocaleSourceString' not found in phar:///usr/local/bin/drush/includes/output.inc on line 0

And then drush stops working and also the web page with an 403 error:

drush ups
Command pm-updatestatus needs a higher bootstrap level to run - you will need to invoke drush from a more functional Drupal environment to run this command.     [error]
The drush command 'ups' could not be executed.                                                                                                                   [error]

Now I’m trying to recover from a full image backup of the disk…


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