Hi guys!
I just got my HA green. I thought it would be plug-and-play but seems like something is wrong.
I disconnected my existing Pi and connected the green via ethernet.
I can see on the screen the new HA command line and IP but I cannot access the GUI (http://homeassistant.local:8123/ or https://192.168.221.52/24:8123)
I also restarted the router which didn’t do much. What do I miss?
Thanks!
On what device are you trying to view it?
via my Mac (and connected to the same network)
I have rigorously the same problem
I noticed two things:
1 On the HA Green console, there are 2 traces:
Core finish service code 1
Core service shutdown
2 On the common network between the mac and the HAGreen, the
Wireshark traces show that the HA Green responds with an RST message to the SYN message of the mac.
Try without the /24
And without the HTTPS.
http://192.168.221.52:8123
@BebeMischa: don’t bother, Stephen has given the solution.
OP is tying to access via httpS where as he doesn’t have TLS configured & he’s trying to use the CIDR as host address…
Saw that after hitting enter 
As for trying to connect through http://homeassistant.local:8123, most likely this still refers to the address of your RPi.
I also think it is somehow linked. What should fix it? restarting the router? other config?
Can you ping 192.168.221.52 ?
???
You don’t change the IP address of a device in the router. All this screenshot says is that there is something at 192.168.221.101, but not what device you are pinging.
Where did you get “101” from?
“This site can’t provide a secure connection”
Because you are using HTTPS:
If you are typing “http://192.168.221.52:8123” and the browser is “automagically” changing it to “https:”, then you need to go into your browser settings to turn off “Automatic HTTPS”.
This can be in your Privacy or Security section- every browser is different.
So I reset the device and installed HA again. now it works smoothly as expected.
Thanks everyone.
Resetting the OS from a microSD seems to have solved the problem.
As indicated at: Resetting the device using an SD card – Home Assistant Green
We can connect to the HA Green and have started the first settings.
