kNN classification error on numeric data

I'm trying to use kNN classification on a dataset with following data structure:

      -39.687        38.54       -3.1409       -1.611       -3.1381    'bear'

I'm getting the following error

>> y = fitcknn(ds,'category');

Error using classreg.learning.FullClassificationRegressionModel.prepareDataCR (line 129)

X must be a numeric matrix.

Error in classreg.learning.classif.FullClassificationModel.prepareData (line 455)

            [X,Y,W,dataSummary] = ...

Error in classreg.learning.FitTemplate/fit (line 205)

                [X,Y,dataPrepOut{1:this.NDataPrepOut}] = ...

Error in ClassificationKNN.fit (line 842)

            this = fit(temp,X,Y);

Error in fitcknn (line 267)

this = ClassificationKNN.fit(X,Y,varargin{:});