Mismatching parentheses.
To correct this just use as follow:
if (!((sd->class_ & MAPID_THIRDMASK) == MAPID_GUILLOTINE_CROSS ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_GENETIC ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_MECHANIC ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_ROYAL_GUARD ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_ARCH_BISHOP ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_RANGER ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_WARLOCK ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_SHADOW_CHASER ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_MINSTRELWANDERER ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_SORCERER ||
(sd->class_ & MAPID_THIRDMASK) == MAPID_SURA))
{
clif_displaymessage (fd, msg_txt (sd, 740)); // This job has no alternate body styles.
return -1;
}