[Python] TypeError: Expected float32, but got auto of type 'str'. Tensorflow error , tell me...

I got TypeError: Expected float32, but got auto of type 'str'. error while fitting the sequential model. I checked my inputs both are numpy.ndarray.

type(xtrain),type(ytrain)
(numpy.ndarray, numpy.ndarray)

model = tf.keras.Sequential()

model.add(tf.keras.layers.Flatten(input_shape = (28,28)))
model.add(tf.keras.layers.Dense(32,activation='relu'))
model.add(tf.keras.layers.Dense(32,activation='relu'))
model.add(tf.keras.layers.Dense(10,activation=tf.keras.activations.softmax))

model.compile(loss = tf.keras.losses.SparseCategoricalCrossentropy,optimizer =
tf.keras.optimizers.Adam(learning_rate=.0001),metrics = ['accuracy'])

model.fit(x =xtrain,y = ytrain,epochs=100)


---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-13-6e8068384c20> in <module>()
----> 1 model.fit(x =xtrain,y = ytrain,epochs=100)

1 frames
/usr/local/lib/python3.7/dist-packages/tensorflow/python/framework/func_graph.py in autograph_handler(*args, **kwargs)
1127 except Exception as e: # pylint:disable=broad-except
1128 if hasattr(e, "ag_error_metadata"):
-> 1129 raise e.ag_error_metadata.to_exception(e)
1130 else:
1131 raise

TypeError: in user code:

File "/usr/local/lib/python3.7/dist-packages/keras/engine/training.py", line 878, in train_function *
return step_function(self, iterator)
File "/usr/local/lib/python3.7/dist-packages/keras/engine/training.py", line 867, in step_function **
outputs = model.distribute_strategy.run(run_step, args=(data,))
File "/usr/local/lib/python3.7/dist-packages/keras/engine/training.py", line 860, in run_step **
outputs = model.train_step(data)
File "/usr/local/lib/python3.7/dist-packages/keras/engine/training.py", line 810, in train_step
y, y_pred, sample_weight, regularization_losses=self.losses)
File "/usr/local/lib/python3.7/dist-packages/keras/engine/compile_utils.py", line 201, in __call__
loss_value = loss_obj(y_t, y_p, sample_weight=sw)
File "/usr/local/lib/python3.7/dist-packages/keras/losses.py", line 141, in __call__
losses = call_fn(y_true, y_pred)
File "/usr/local/lib/python3.7/dist-packages/keras/losses.py", line 245, in call **
return ag_fn(y_true, y_pred, **self._fn_kwargs)
File "/usr/local/lib/python3.7/dist-packages/keras/losses.py", line 752, in __init__ **
from_logits=from_logits)
File "/usr/local/lib/python3.7/dist-packages/keras/losses.py", line 227, in __init__
super().__init__(reduction=reduction, name=name)
File "/usr/local/lib/python3.7/dist-packages/keras/losses.py", line 88, in __init__
losses_utils.ReductionV2.validate(reduction)
File "/usr/local/lib/python3.7/dist-packages/keras/utils/losses_utils.py", line 82, in validate
if key not in cls.all():

TypeError: Expected float32, but got auto of type 'str'.

Continue reading...