为什么在构建神经网络时出现StopIteration错误

Question

enter image description here如何在此处解决StopIteration错误。我正在尝试为图像分类建立CNN。

from keras.preprocessing.image import ImageDataGenerator
train_datagen = ImageDataGenerator(
    rescale=1./255,
    shear_range=0.2,
    zoom_range=0.2,
    horizontal_flip=True)
test_datagen = ImageDataGenerator(rescale=1./255)
train_set = train_datagen.flow_from_directory("training_set", target_size=(64, 64),
    batch_size=(64,64),
    class_mode='binary')
test_set = test_datagen.flow_from_directory( "test_set",
    target_size=(64, 64),
    batch_size=32,
    class_mode='binary')
model.fit_generator(
    train_set,
    steps_per_epoch=8000,
    epochs=25,
    validation_data=test_set,
    validation_steps=2000)