Google AutoML Error after 24 hours of training

Question

I've prepared my dataset to work with Google Cloud AutoML vision and adjusted my training hours to 11 hours. my dataset contains 620K images in 600 categories. the training took 24 hours (though I only requested 11) and after that, it gave me this error.

Hello Google Cloud AI Customer, 
Due to an error, AutoML Vision was unable to process your dataset "axv_image". There will be no charge issued for this job. 
To see a more detailed error log, go back to your dataset. 
Additional details


Last error message

Please reference 406547347077053119 when reporting errors.

I checked the additional details section and it says the below

Please refer to this issue by its reference code ICN406547347077053119 when reporting errors.

This has been happening over the last week and it occurred to me 4 times. I want to know what is the exact error to rectify my dataset, or where should I report such an incident. it is really annoying to show meaningless error codes without descriptions!