Training data error superClass

[Saadi4469]

I am trying to perform a supervised classification using polygon spatial data and a RGB raster. However, I am getting the following error even though rgdal picks up the shapefile as a SpatialPolygonsDataFrame.

How can I fix this?

Error Error: traingData must POINTs or a POLYGONs

Code

SC_RF = superClass(img = CR, model = "rf", trainData = Training_Data,
                         responseCol = "Feature")