500 Server Error for http+docker://localhost/

Installation
1

Dear all,

I have a Raspberry Pi5, used the Raspberry Pi Imager to write Home Assistant on the SD card.
After I started, switched on the Advanced Mode, and configured the basics, I tried to install MOSQUITTO BROKER from the Add-on store.
Everytime I get the following error:

2025-05-18 20:10:18.279 ERROR (MainThread) [homeassistant.components.hassio] Failed to to call /addons/core_mosquitto/install - Can’t install homeassistant/aarch64-addon-mosquitto:6.5.1: 500 Server Error for http+docker://localhost/v1.48/images/create?tag=6.5.1&fromImage=homeassistant%2Faarch64-addon-mosquitto&platform=linux%2Farm64: Internal Server Error (“received unexpected HTTP status: 500 Server Error”)

I wiped the SD-card and redid the whole process, again. No success.

Reason why I started over the Configuration, was that I also had this error when I tried to update Terminal & SSH, and later other Add-ons. I believed that with a fresh install, it all would be better.

During my search, I read an answer that possibly the device had no internet connection. I confirm that internet is live.

I am looking forward to your reply. Your help is much appreciated.

2

My apologize to reply on my own post.
I cannot imagine that I am the only one with this error.
Is there information missing in my initial post that it is impossible to answer?

What can I do to get more response in my support request?

3

I managed to find the issue.

I guess a change was made at the Home Assistant servers by ‘increasing security’.
As I my LAN is connected via a VPN, connections via my VPN are blocked.
If I connect the RPi directly to the internet, no VPN active, then I can download the add-on apps.
Maybe a possibility to the Home Assistant team to look into this.

Than you in advance!