if it is placed in a wrong group (for example, max_print_height does not belong to print settings, but a printer settings, so Slic3r will now complain about it being in print settings, and it will remove the value from the print settings).
if it is placed in a wrong group (for example, max_print_height does not belong to print settings, but a printer settings, so Slic3r will now complain about it being in print settings, and it will remove the value from the print settings).