In language file language\en\install_new.php is:

'MODULE_NOT_FOUND_DESCRIPTION' => 'No module is found under the service definition “%s” is not defined.',

and similar:

'TASK_NOT_FOUND_DESCRIPTION' => 'No task is found under the service definition “%s” is not defined.',

I think there should be comma (in both sentences) after the word "definition":

'TASK_NOT_FOUND_DESCRIPTION' => 'No task is found under the service definition, “%s” is not defined.',

Here is short discussion about it: https://area51.phpbb.com/phpBB/viewtopic.php?f=81&t=48396&p=283736#p283721