error in train_selection_ensemble()

[HexuanLiu]

I'm following the example in metalearning_example, and I got to the steps of training the learning model. When running:
meta_model <- train_selection_ensemble(train_data$data, train_data$errors)
I encountered the following error:
Error in rowSums(preds) : 'x' must be an array of at least two dimensions

I'm not sure if the problem is with the customxhboost package or with the error_softmax_obj function that calls rowSums(preds). Any help would be appreciated.

[leogeogh]

same issue, any help would be appreciated too.