Data shows n/a in a row where a value should be, why does it not show the code its supposed to show?

Question

TrainAttempt$PriceGuess <- with(TrainAttempt, 
    0+(LotFrontage*1)+(LotArea*1)+
    (MasVnrArea*1)+(BsmtFinSF1*1)+
    (BsmtFinSF2*1)+
    (BsmtUnfSF*1)+
    (TotalBsmtSF*1)+
    (GrLivArea*1) + 
    (BsmtFullBath*1) + 
    (BsmtHalfBath*1) +  
    (FullBath*1) + 
    (HalfBath+0) + 
    (BedroomAbvGr*1)  + 
    (KitchenAbvGr*1)  + 
    (TotRmsAbvGrd*1)  + 
    (Fireplaces*1)  + 
    (OpenPorchSF*1) + 
    (GarageArea*1)  + 
    (WoodDeckSF*1)  + 
    (OpenPorchSF+0) + 
    (EnclosedPorch*1) + 
    (ScreenPorch*1)  + 
    (PoolArea*1)  + 
    (MiscVal*1))