I was having the same issue. I use joblib and work was done. In case if someone wants to know other possibilities.
save the model to disk
from sklearn.externals import joblib
filename="finalized_model.sav"
joblib.dump(model, filename)
some time later… load the model from disk
loaded_model = joblib.load(filename)
result = loaded_model.score(X_test, Y_test)
print(result)