Dont do Opus Magnum after completing the game, I guess (SPOILERS)

[Jinksio]

I completed the main story some time ago, and noticed I didnt yet complete the quest Opus Magnum. It was on the "get the dress, bathmaid and book" part (probably since I didnt get the book after completing For Whom The Bell Tolls and used the blacksmith's help instead). So I went and bought the dress, got the book and asked for the woman to pose as a noble at the wedding in Semine, which already ended and Semine had a "minor microwave accident" after Henry and Hans went there. I talked to Enneleyn and convinced her to take part in the wedding. After getting rid of my armor, I said I was ready to go to the wedding. After that she proceeded to walk all the way to the "on a scale from raw to medium rare, CONGRATULATIONS" Semine, where she stood there. I couldnt speak to her too, though since I didnt do the quest, I dont know if it was intended. In the mean time I couldnt skip time, fast travel or call my horse, so I walked to the mill to give the miller the book, but alas! He only cared about training me in thievery and alchemy (which, due to the fact that I couldnt skip time, was taught to me instantly). Then I went to beat up his workers and returned to Semine. On the way I killed a Cuman and stole his horse so I could get there faster. Upon witnessing the woman was in Semine, I shot her with my reinforced heavy crossbow, missed, reloaded, chased her, shot again, missed, then took my bow and shot her again to find out she is an essential NPC and arrows passed through her. Fortunately, expecting a glitched outcome (though I thought that I'd visit the wedding again and everyone would act like nothing burned) I used a weak Saviour Schnapps before talking to her. After reloading the save, everything was back to normal.