Error in MICE package in R

Question

I am getting the error when i run the below code for imputing the missing values through MICE package in R

url <- "https://raw.githubusercontent.com/selva86/datasets/master/Cars93_miss.csv"
ca <- read.csv(url)
im_ca <- mice(ca, MaxNWts = 4000)

iter imp variable
  1   1  Manufacturer  Model
Error in augment(y, ry, x, ...) : 
  Maximum number of categories (50) exceeded

Could someone help me as why am i getting this error? Any help is appreciated.

Regards,

Mohan