I disabled (not removed) Watchtower. It seems to have fixed the problem - for now
I had this same error appear this morning. Im running hassio through Window Hyper V.
I tried several things, but shutting the virtual machine down and restarting seems to have done the trick, so a simple power off and on again may fix this (a restart through homeassistant didn’t work for me)
Same issue here. Will try powerdown, restart from HA doesn’t work.
Same here, on the latest 107 on rpi3. I can see my sensors and use some switches but performance is VERY poor and the developer tools do not work either. SMB access is also not possible.
I tried rebooting, but now the connection times out before the UI is visible.
Had the same issue. My install method is Ubuntu with HA loaded onto this. It is a case of updated the Ubuntu OS. I ran through the following commands, rebooted and it works
Hassio on rpi4 did this as well. ssh in (via a terminal, not web interface as that did not work) and rebooted. it came up fine. looks like the supervisor got a few updates yesterday…
I had this problem yesterday. Iam using docker.
Solution:
Docker image ls -a
- look for the supervisor module, and copie the ID.
Docker image rm ‘id’ - this wil delete the supervisor.
docker pull homeassistant/amd64-hassio-supervisor - this wil download a new supervisor image
Docker container start ‘super visor name’
OR
Restart server.
2 Likes
I just tried to update supervisor from 216 to 217 if I’m not mistaken and now I can no longer open the tab.
The error is the same “Unable to load the panel source: /api/hassio/app/entrypoint.js.”
Before I tried to restart the supervisor via cli with no success. Then unfortunately I decided to reboot the Pi and now I don’t have access in ssh.
So I’m stuck out of the Pi.
I have hassio installed on a Pi4 with HA .108.3
Last resort worked. I detached power cable from Pi and waited few minutes than I powered it on back and HA brought back to life.
Now I can normally ssh in.
I checked the supervisor versione via cli and il looks it is the 217.
Anyway when I update something in hassio I have to cross my fingers every time…
Restarting the host solved the issue for me.
A power cycle (not soft reset) fixed it for me.
I’m going to share my fix for “Unable to load the panel source: /api/hassio/app/entrypoint.js.” issue here in case it helps anyone. Just so you know the background, I was trying to move a previous instance of hass.io from an ubuntu 16.04 lxc container into an ubuntu 18.04 VM. Banged my head around for a few hours before figuring this out so here are my steps:
1 sudo -i
- Make sure you have network-manager installed or install with apt-get update && apt-get -y install network-manager
2. sudo systemctl stop hassio-supervisor.service
3. docker stop $(docker ps -a -q) && docker rm $(docker ps -a -q)
- You may also need to do docker rmi $(docker images -a -q) but I didn’t have to
4. Move your files over from previous installation if you need to
5. sudo systemctl start hassio-supervisor.service - at this point everything started except homeassistant docker container itself (which you can check by running docker ps) so my final step was…
6. reboot now
This seemed to do everything needed to restart the containers with proper networking.
3 Likes
Hi,
Just follow this steps and now I no longer have the supervisor tab.
I have the same setup. Hassio on docker on ubuntu 18.04 VM.
Am I missing a step here. Should I update the supervisor container. (Currently its 214).
Thanks
I posted this in another thread, but this is what solved my previously related issue.
1 Like
Thanks.
Unfortunatelly didn’t worked for me. so I just created a new VM and installed home assistant from scratch… Now I have a diferent issue 
I have portainer running, so I just clicked on the stopped container, hassio_supervisor, and then ‘Recreate’ and told it to pull from the latest image (219), so as not to use the one it was failing on (214). After a short while, everything was up and running again.
I just installed Home Assistant on a new Intel Nuc running Ubuntu. I got this error today. Doing a hard reboot (sudo shutdown now) fixed it.
I just experienced this fault. It started yesterday as we where going to bed, had done nothing to my system at that time so completely out of the blue.
This morning I started to search around for a fix.
My system:
Rp 3b
SD Card
HA 107.7 (had not updated at that time)
HACS installed
Since I couldn’t get in to the supervisor I was unable to reboot the system. I have SSH add-on (Terminal & SSH) installed, but the somehow the configuration of the port was set to “null”. So I could not get into the system to reboot. The only thing left was to pull the plug 
I was lucky and the system booted up fine.
As soon as the system was up I made a new full snapshot.
Then I looked into the ssh problem and found the issue with the port, I changed that to 22 and made sure ssh worked by using the terminal.
Then I updated the system completely to the latest HA and operating system.
So far the system is working fine, I only had one invalid config. That was an add-on from the HACS, spotcast. This add-on had recently stopped working because of Spotify changing some things. I don’t think that caused this fault on my system.
If my SSH would have been working I would have tried this before doing a hard reboot.
This really made me question having my system on an SD card for sure, I have had this install since late last year with no issues and a great setup I rely on. If I have the same fault again I will report back.
I had same issue this morning and fixed it. I’m running Home Assistant version 0.108.9 and Supervisor version: 220 on OMV Docker. From Portainer I restarted Supervisor and everything seems working now.