Some of the files in the training (syn10495809) and test (syn10701954) sets were completely null except for the timestamp values. These files have now been removed from the sample submission template (syn11026476) we provided earlier.   If you've already written code that imputes features for these null files -- no need to change anything. The null files won't be used in the training on the train set or the scoring on the test set on our end.   Some files are a mix of NaN values and floats (besides the timestamp). These files have been left in the submission template and will still be trained on or scored.