Thanks for your reply Saeran, and for giving me hope my playthrough isn't at an end. I have the hammer, but I was meant to meet Vos in the sewers to then go into the prism and free Orpheus. Is there another way/path, other than with Vos's aid?
Larian tech support said they know its a known bug, but couldn't provide more help than that.
You will have an option to free Orpheus at the very end of the game as long as you keep the hammer in your inventory, it is not possible to miss it as it is part of the main quest. Voss cannot take you to the prism anyway, so talking to him is optional.
