Error when logging into admin. Bitrix section, how to win?

Question

1C-Bitrix

When entering the admin panel, a white page with errors. Bitrix 18.00, PHP - 7.0
Call to undefined method Bitrix\Landing\Manager::isB24() (0)
/home/v/vashotkd/russia-otdih.ru/public_html/bitrix/modules/landing/admin/menu.php: 12
And in the public part, the components are not edited. The frame appears but nothing happens.
Error in console:
VM22297:85 Uncaught ReferenceError: bxSession is not defined
at VM22297:85
(anonymous) @ VM22297:85
VM22298:89 Uncaught ReferenceError: bxSession is not defined
at VM22298:89
(anonymous) @ VM22298:89
VM22308:186 Uncaught TypeError: BX.COpener is not a constructor
at VM22308:186
(anonymous) @ VM22308:186
core_admin.js:974 Uncaught TypeError: BX.COpener is not a constructor
at Object.__init (core_admin.js:974)
at kernel_main.js?1573549587237322:8