Re: Crafted the murder knife but then it reset and have to recraft it

@kbone97 What system are you on?
Do you have a save from before you tried to craft the knife?

Did you remember to go and speak to the assassin trainer after crafting the knife? This must be done to choose your specialisation and gain access to the skill tree. I believe the rogue trainers can be found next to the barn where Blackwall is, near the door to the kitchen.