Masterwork Tevinter longsword question.

Hey i was woundering about the masterwork tevinter longsword. it seems like the drop on that one is bugged.

For some reason afther 4 playthroughes it never drops and afther 10hours+ farming for it, it still dont drop.

so was wondering if this is a real schematic or just a fake?

And pc users say the only way to get it is with the usage of a cheat engine.