Thank you!
Yes I can backup a new blank site. I think I found the error from the error logs which complains about: ERR_CHILD_PROCESS_STDIO_MAXBUFFER. It seems to complain about exceeding Nodejs buffer size. Could you tell me more about it and how acn I resolve this error to make my backup. My local version is Version 9.2.5+6810
I was able to find this thread but apparently the problem resolved on its own for that person Error: stderr maxBuffer length exceeded - #4 by Nick-B