+remove_root = You are not allowed to remove the root directory.
+rename_root = You are not allowed to move/rename the root directory.
+no_users = It seems that your system doesn't support users and groups.
+not_owner = You are not the owner of {FILE}, so you are not allowed to change the mode and the group.
+invalid_group = '{GROUP}' seems to be an invalid group name. Please check it and try again.