Hi Ariful,
Sorry for the Inconvenience.
We are able to reproduce the reported issue (Not able to get names of selected file or files when uploading files at FRONT END (beforeUpload Event)). We have confirmed this as a defect and logged an Issue report for this. Fix for this issue will be included in our upcoming main release for Vol 1 2017, which is expected to be roll out at the first week of February 2017.
Regards,
Ashokkumar B.