Package check result: ERROR

Check: examples, Result: ERROR
  Running examples in ‘traineR-Ex.R’ failed
  The error most likely occurred in:
  
  > base::assign(".ptime", proc.time(), pos = "CheckExEnv")
  > ### Name: train.xgboost
  > ### Title: train.xgboost
  > ### Aliases: train.xgboost
  > 
  > ### ** Examples
  > 
  > 
  > ## No test: 
  > # Classification
  > data("iris")
  > 
  > n <- seq_len(nrow(iris))
  > .sample <- sample(n, length(n) * 0.75)
  > data.train <- iris[.sample,]
  > data.test <- iris[-.sample,]
  > 
  > modelo.xg <- train.xgboost(Species~., data.train, nrounds = 10, maximize = FALSE)
  Warning in check.deprecation(deprecated_train_params, match.call(), ...) :
    Passed invalid function arguments: eval_metric. These should be passed as a list to argument 'params'. Conversion from argument to 'params' entry will be done automatically, but this behavior will become an error in a future version.
  Warning in throw_err_or_depr_msg("Parameter '", match_old, "' has been renamed to '",  :
    Parameter 'watchlist' has been renamed to 'evals'. This warning will become an error in a future version.
  [1]	train-mlogloss:0.738285 
  [2]	train-mlogloss:0.527359 
  [3]	train-mlogloss:0.390308 
  [4]	train-mlogloss:0.296220 
  [5]	train-mlogloss:0.229717 
  [6]	train-mlogloss:0.181500 
  [7]	train-mlogloss:0.145874 
  [8]	train-mlogloss:0.120036 
  [9]	train-mlogloss:0.100249 
  [10]	train-mlogloss:0.084281 
  > modelo.xg
  ##### xgb.Booster
  call:
    xgb.train(params = params, data = train_aux, nrounds = nrounds, 
      verbose = verbose, print_every_n = print_every_n, early_stopping_rounds = early_stopping_rounds, 
      maximize = maximize, save_period = save_period, save_name = save_name, 
      xgb_model = xgb_model, callbacks = callbacks, eval_metric = "mlogloss", 
      watchlist = watchlist)
  # of features: 4 
  # of rounds:  10 
  callbacks:
     evaluation_log 
  evaluation_log:
    iter train_mlogloss
   <int>          <num>
       1     0.73828501
       2     0.52735880
     ---            ---
       9     0.10024916
      10     0.08428103
  > prob <- predict(modelo.xg, data.test, type = "prob")
  Error in if (predleaf) { : argument is of length zero
  Calls: predict ... predict.xgb.Booster.prmdt -> predict -> predict.xgb.Booster
  Execution halted