I managed to get the Silver Sword of Astral Plane in Act 1. While Lae'zel was occupied talking to Voss, I sneaked up and used Shadowheart to force Voss to drop his sword. After some time I managed to do it and even Lae'zel didn't turn against my party. We wiped out the rest of the Githyanki patrol, but for some reason I can no longer enter the dialogue with her. At all. So I can't have even get her to leave my current party. Initially there was even a quest mark above her, but that is gone. Does anyone know what is the solution after using the exploit? Or should I reload the game? Does the same happen even if I get the sword without Lae'zel being at the time in my party? I tried killing her and reviving in the camp, but that doesn't work.

I've definitely pulled this off without Lae'zel in my party, and she still talks to me even while wielding the sword.

My wild guess is that some Lae'zel variable doesn't get set when you pick a fight in the middle of her dialogue, so maybe reload and try keeping her out of the dialogue.