Maybe I have to add that I have the latest (stable) Arx Libertatis patch installed, but I cannot enchant this saber...

I've tried Amikar and Garlic.

Is this a bug or working as intended?

cheers

This bug also seems to be for the 1H sword "Ciprian Long Sword of Force"....

Seems these - like other "special swords" (meteor...) - can only be enhanced with poison, nothing else.

That's my conclusion as well; these are all magically enhanced swords; I truly wish one could make them indestructible anyhow, seeing as there are only a few stones in the world of Arx; but at least the best items already are indestructible :-)

Named items cannot be enchanted! Unless they are the unidentified armor pieces that special Ylside woman drops (hidden spell that summons a devil).