cannot_finish_ui_if_not_setting_ui

I just updated our Moodle from 3.0.x to 3.4.x and now we cannot backup any course because we get the error cannot_finish_ui_if_not_setting_ui 

Here is my debug messages text that appears when this happens:

Debug info: 

Error code: cannot_finish_ui_if_not_setting_ui 

$a contents:

×Stack trace:

line 167 of \backup\controller\backup_controller.class.php: backup_controller_exception thrown

line 135 of \backup\util\ui\backup_ui.class.php: call to backup_controller->finish_ui()

line 146 of \backup\backup.php: call to backup_ui->execute()