When using the sandbox, you can be confronted to a port forwarding issue.
For example, if you try to access AppTimelineServer webUI on port 8188, you’ll have a “Connection refused”.
This is weird since the process is listening :
[root@sandbox ~]# nc -nz 127.0.0.1 8188 Connection to 127.0.0.1 8188 port [tcp/*] succeeded!
You’ll have to configure the VirtualBox port forwarding to add this port which has not been added :