Error in annotate.py "'NoneType' object has no attribute 'data'"

[samiarja]

I am using python 3.6.x with windows 10 OS.
I am encountering an error while running annotate.py script, I did a minor change for the code to make it compatible with python 3.
I knew the code run smoothly when the below was show in the terminal.

Event-based vision module imported
State file found.
State file updated.
Please enter your name: Sami
Press [a] to add a track, [c] to mark this file as complete and continue to the next file, or [x] to exit.A
Annotating track number 0
Click in window and press spacebar to begin tracking

however, I followed all the instruction from the code and when the image open I tried to click on spacebar to begin tracking, but this what I got

Traceback (most recent call last):
File "C:/Users/Sami/Desktop/Companies/The MARCS Institute/Code Testing/DV Software Code/event-Python-master/annotate.py", line 530, in
main()
File "C:/Users/Sami/Desktop/Companies/The MARCS Institute/Code Testing/DV Software Code/event-Python-master/annotate.py", line 509, in main
add_track(annotation_state.output_subfolders[incomplete_file_ind], num_track_files, TD, annotated_by, annotation_state.source_files[incomplete_file_ind])
File "C:/Users/Sami/Desktop/Companies/The MARCS Institute/Code Testing/DV Software Code/event-Python-master/annotate.py", line 374, in add_track
track = annotate_tracks(TD, 100000)
File "C:/Users/Sami/Desktop/Companies/The MARCS Institute/Code Testing/DV Software Code/event-Python-master/annotate.py", line 186, in annotate_tracks
tmax = np.max(TD.data.ts)
AttributeError: 'NoneType' object has no attribute 'data'

Is this a bug? I am using nmnist.hdf5 dataset

thanks
Sami