My log says I have found the recepy in Imal's book and I do have the ingredients: Voxwood + Bottled Voice but I can get them to combine. It says "Invalid Combination"

Take a look at the pics

Log Entry: http://images.akamai.steamuserconte...AFB83D54CF1583DBDDB49E4AA1785100C8235C1/

Bottled Voice:
http://images.akamai.steamuserconte...3B2801463C51C3A85876A249F9BF030F034EE68/

Voxwood:
http://images.akamai.steamuserconte...5E4E596A96A7268055B696E03846379B144B5A7/

Forced combination Voxwood + Bottled Voice: Nothing
http://images.akamai.steamuserconte...F4813AFB36B5A49913EFE97EC24E6840BBA3A6F/

Forced combination Bottled Voice + Voxwood: Nothing
http://images.akamai.steamuserconte...25B601368608D1AB9FB92C665E4E2CF3B3BEEA5/

Tried to combine them where I kill Imal but I didn't help. Please help me.