Thanks so much sir. thanks for the help here for these days. i am really not sure what is going on here. just now, i tried your way to launch notebook using anaconda navigator as you suggested, it actually worked. really surprised. but then i tried again to launch jupyter notebook using normal way. it also successfully. seems as if the issue never happen before. really weird.
anyway, since the problem resolved itself, i think i am good now on my side. thanks so much for the help and your patience. really appreciate it.
Thanks,
Alex