Hdevelop Deep Learning Code Error (User defined exception ('throw') (HDevelop error code: 21001))

Question

I'm new to MVTec Halcon Deep Learning, I labelled my images and exported a hdict. file with MVTec Deep Learning Tool, then I tried to change some code of "classify_pill_defects_deep_learning_1_preprocess" Halcon example code, when it reached "preprocess_dl_dataset (DLDataset, DataDirectory, DLPreprocessParam, GenParam, DLDatasetFileName)" , there's error that display :

Unhandled program exception:

User defined exception ('throw') (HDevelop error code: 21001)
while calling 'throw' in procedure 'gen_dl_samples' line: 169.

User data:
    ['For image_id 1 the key \'image_label_id\' is missing. Missing keys can be ignored using the GenParam ignore_missing_labels.']

it says missing labels? but I checked that all images are labelled accordingly. Additionally, is ignoring missing keys ok? if yes how?

Thanks in advance !

I tried to understand how the code works but I'm new to it and the resources on internet is not that much. I'm expecting to know how to change the code and train my own deep learning model.