I faced same issue under Windows 7 – http://127.0.0.1:8000 not working at all.
It turned out, that there is already a process that listens on port 8000.
My simple resolution was to just map host port 8001 to guest port 8000.
OVA: HDP 18.104.22.168
resolution: map host port 8001 to guest port 8000
url for HUE: http://127.0.0.1:8001/