Problems uploading a new dataset to OpenNeuro

I have a problem uploading a new dataset. Although I fix all of the errors, the process gets stuck in step3 (validation), with no more progress and no error. Any help is appreciated.
As another related question, is it possible to upload a dataset and add new more data to it after some time?

Best Regards,

Is the dataset able to pass validation here?:

Modifications and additions to datasets are allowed after upload.

Finally to confirm, which browser are you using? Is there anything being printed to the javascript console of your browser?