Warning: Undefined array key "type" in /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/inc/class-migrate.php on line 93

Fatal error: Uncaught TypeError: sort(): Argument #1 ($array) must be of type array, null given in /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/inc/class-migrate.php:94
Stack trace:
#0 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/inc/class-migrate.php(94): sort(NULL)
#1 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/inc/class-migrate.php(30): BackWPup_Migrate::organize_jobs_by_type(Array)
#2 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/inc/class-install.php(30): BackWPup_Migrate::migrate()
#3 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/backwpup.php(74): BackWPup_Install::activate()
#4 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/backwpup.php(195): BackWPup->__construct()
#5 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-includes/class-wp-hook.php(324): BackWPup::get_instance('')
#6 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#7 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#8 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-settings.php(559): do_action('plugins_loaded')
#9 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-config.php(85): require_once('/customers/9/5/...')
#10 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-load.php(50): require_once('/customers/9/5/...')
#11 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-blog-header.php(13): require_once('/customers/9/5/...')
#12 /customers/9/5/1/spiegelhol.nl/httpd.www/blog/index.php(17): require('/customers/9/5/...')
#13 {main}
  thrown in /customers/9/5/1/spiegelhol.nl/httpd.www/blog/wp-content/plugins/backwpup/inc/class-migrate.php on line 94