mnist.load_data()遇到IOError: CRC check failed 0xc187cf56L != 0x14c5212fL

i try to load the mnist dataset by writing :
from keras.datasets import mnist
(x_train,y_train),(x_test,y_test)=mnist.load_data()

but i get the following error :
IOError: CRC check failed 0xc187cf56L != 0x14c5212fL

how can i fix this error??

solutions:

rm ~/.keras/datasets/* and retry.