The special effect " At the end of your turn, raise a Corpse as a 1/3 Risen Footman with Taunt" is so buggy and occasionally works. Most of the time it never gets triggered.
If you have no corpses, then of course it won’t trigger.
Do you know what corpses are?
“Raise a corpse” isn’t just flavor text. Corpses are an actual in-game resource, kind of like mana.