h2o.exceptions.H2OResponseError: Server error water.exceptions.H2OKeyNotFoundArgumentException
<p>I get this error when I run the code below.</p>

<pre><code>import h2o
from h2o.estimators.gbm import H2OGradientBoostingEstimator as GBM
from sklearn import datasets
import numpy as np
import pandas as pd

h2o.init(ip='192.168.0.4',port=54321)

# writing data to CSV so that h2o can read it
digits = datasets.load_digits()
predictors = digits.data[:-1]
targets = digits.target[:-1]
record_count = targets.shape[0]
targets = targets.reshape([record_count,1])
data = predictors
data = np.concatenate((data, targets), axis=1)
write_df = pd.DataFrame(data).to_csv(path_or_buf='data.csv',index=False)
model = GBM(ntrees=3,distribution='multinomial',max_depth=3)
everything = h2o.import_file(path='data.csv')
everything[64] = everything[64].asfactor()
model.start(training_frame=everything,x=list(range(64)),y=64,validation_frame=everything)

# model seems to be None for some reason
predictions = model.predict(everything)
</code></pre>

<p>The specific error is:</p>

<pre><code>Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  File "/Users/ryanzotti/anaconda/lib/python3.4/site-packages/h2o/model/model_base.py", line 148, in predict
    j = H2OJob(h2o.api("POST /4/Predictions/models/%s/frames/%s" % (self.model_id, test_data.frame_id)),
  File "/Users/ryanzotti/anaconda/lib/python3.4/site-packages/h2o/h2o.py", line 83, in api
    return h2oconn.request(endpoint, data=data, json=json, filename=filename, save_to=save_to)
  File "/Users/ryanzotti/anaconda/lib/python3.4/site-packages/h2o/backend/connection.py", line 259, in request
    return self._process_response(resp, save_to)
  File "/Users/ryanzotti/anaconda/lib/python3.4/site-packages/h2o/backend/connection.py", line 586, in _process_response
    raise H2OResponseError(data)
h2o.exceptions.H2OResponseError: Server error water.exceptions.H2OKeyNotFoundArgumentException:
  Error: Object 'None' not found in function: predict for argument: model
  Request: POST /4/Predictions/models/None/frames/py_1_sid_a5e2
</code></pre>

<p>There are no other errors prior to this one.</p>

<p><strong>H2O Version:</strong> 3.11.0.3645</p>

<p><strong>Python Version:</strong> 3.4.4</p>

<p>Change <code>model.start</code> into <code>model.train</code> (3rd line from the bottom), and it should work.</p>

<p>The documentation for <code>model.start()</code> method says "Train the model asynchronously". This means that the model is being trained in the background and is not available right away for the prediction call.</p>

<p>The <code>model.train()</code> method on the other hand waits until the training is completed before continuing.  </p>

python h2o