how do I create a lightsaber I have all the parts and when I talk to Bao-Dur he asks what kind of lightsaber I want but then nothing happens is it a bug?

It should just show up in your inventory. If it didn't, go back to an earlier save game point & try again. I haven't heard anyone else mention this as a bug.

but I can't even choose my crystal the dialogue just ends and when I talk to him again I still have the parts because he didn't created a ligthsaber

I "fixed it" I had a blue cristal in my inventory I sold it then Bao-Dur created a lightsaber don't know were he got the critsal though

Hmmm....I'm glad you got it fixed...I had different color crystals in inventory when I spoke with him...When asked "What color" I had to pick from the colors I had in my inventory.

 

I must say though...I'm really liking the different color variations that were added to this game. A silver lightsaber blade is becoming awful comfortable with me.