Error Contao 3.5.28

[teacherrolf]

Nach dem Update von 3.5.27 auf 3.5.28 erscheint folgende Fehlermeldung:

Warning: in_array() expects parameter 2 to be array, null given in system/modules/core/library/Contao/System.php on line 160
#0 [internal function]: __error(2, 'in_array() expe...', '/hp/ci/aa/ui/ww...', 160, Array)
#1 system/modules/core/library/Contao/System.php(160): in_array('getInstance', NULL)
#2 system/modules/core/library/Contao/Widget.php(1402): Contao\System::importStatic('tl_subcolumnsCa...')
#3 system/modules/core/classes/DataContainer.php(268): Contao\Widget::getAttributesFromDca(Array, 'subcolumns', NULL, 'subcolumns', 'tl_settings', Object(Contao\DC_File))
#4 system/modules/core/drivers/DC_File.php(253): Contao\DataContainer->row()
#5 system/modules/core/classes/Backend.php(650): Contao\DC_File->edit()
#6 system/modules/core/controllers/BackendMain.php(131): Contao\Backend->getBackendModule('settings')
#7 contao/main.php(20): Contao\BackendMain->run()
#8 {main}

Fatal error: Class 'tl_subcolumnsCallback' not found in /hp/ci/aa/ui/www/mal-sehen/Livingsenses_2017/system/modules/core/library/Contao/System.php on line 160

[dmolineus]

Seems like something went wrong. Maybe call composer update again? Furthermore the raised issue is referencing subcolumns. So it' not an issue of Bootstrap.