This problem appears with the DEC/OSF1 version of the compiler only, whenever starting the compiler with the -g loop option. The reason is that the files lib/aldor_gloop.ao and lib/aldor_gloopd.ao delivered with that version of the compiler are obsolete. Simply replace them by their proper versions available here: aldor_gloop.ao and aldor_gloopd.ao (press 'Shift' while clicking to save them).