You still haven’t posted the error message. 
However, based on the structure of the dataset, it seems that the input images and target masks are images which are stored in the train and train_labels folders, respecively.
In your current code snippet you are trying to pass a csv file and read the the image and label from columns 0 and 1.
Could you explain the code a bit and where this csv can be found?
There is a class_dict.csv, which seems to contain a color mapping to map the target mask colors to class indices.