Also seeing similar issues.
Plugin was removed and then added back in but this hasn’t resolved the issue.
Seeing the following error messages when attempted to ‘Add New Job’:-
Warning: include(/var/sites/g/gwpra.org.uk/public_html/wp-content/plugins/backwpup/inc/../sdk/Aws/Symfony/Component/ClassLoader/UniversalClassLoader.php) [function.include]: failed to open stream: No such file or directory in /var/sites/g/gwpra.org.uk/public_html/wp-content/plugins/backwpup/inc/class-destination-s3.php on line 6
Warning: include() [function.include]: Failed opening '/var/sites/g/gwpra.org.uk/public_html/wp-content/plugins/backwpup/inc/../sdk/Aws/Symfony/Component/ClassLoader/UniversalClassLoader.php' for inclusion (include_path='.:/usr/local/lib/php') in /var/sites/g/gwpra.org.uk/public_html/wp-content/plugins/backwpup/inc/class-destination-s3.php on line 6
Fatal error: Class 'Symfony\Component\ClassLoader\UniversalClassLoader' not found in /var/sites/g/gwpra.org.uk/public_html/wp-content/plugins/backwpup/inc/class-destination-s3.php on line 7