ML.Net "No valid instances encountered during data loading" error while loading data file

Question

error screen shot

var testDataPath = "model.csv";
IDataView trainingDataView = mlContext.Data.LoadFromTextFile<MovieRating>(trainingDataPath, hasHeader: true, separatorChar: ',');
ITransformer model = trainerEstimator.Fit(trainingDataView);

while returning the transformer i have an error like

No valid instances encountered during data loading

How can i solve it? Any ideas?

Answer 1

I was experiencing this, and solved reviewing my dataset (do they fit into MovieRating).

In my case I was missing the separatorChar: ',' when loading the data view. After including it, the exception was not thrown.