vivanda

Same here, critical error. I went to PHP and deactivate all plugins but still have no acces to the admin panel. How to fix this?

Fatal error: Uncaught Error: Class “sapLibrary_2_6_21_rtb” not found in /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-content/plugins/restaurant-reservations/lib/simple-admin-pages/simple-admin-pages.php:49 Stack trace: #0 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-content/plugins/restaurant-reservations/includes/Settings.class.php(1062): sap_initialize_library(Array) #1 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-includes/class-wp-hook.php(324): rtbSettings->load_settings_panel(”) #2 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array) #3 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #4 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-settings.php(695): do_action(‘init’) #5 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-config.php(125): require_once(‘/customers/6/3/…’) #6 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-load.php(50): require_once(‘/customers/6/3/…’) #7 /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-blog-header.php(13): require_once(‘/customers/6/3/…’) #8 /customers/6/3/8/vivanda.be/httpd.www/mivino/index.php(17): require(‘/customers/6/3/…’) #9 {main} thrown in /customers/6/3/8/vivanda.be/httpd.www/mivino/wp-content/plugins/restaurant-reservations/lib/simple-admin-pages/simple-admin-pages.php on line 49

I cannot enter to admin panel due to this error message. I went to FTP and disabled all plugins but still have the same error message. How can i downgrade in FTP?