OH3: HABpanel in new browser results in a black page

[After research and trial, modified to a simple issue]

When I call in my PC browser, it works.
This is the browser I developed the panel.

I saved this panel as TrialPanel


When I call the same link on any other machine/browser I get a black page.

When I remove the word TrialPanel, I get this screen:

Clicking on the hamburger, results in this:

But there is no TrialPanel entry I can select.

The docs says: got to PaperUI and Configuration, which does not exist in MainUI.
Yes, I looked at all menu items, but can’t find anything related to HABpanel.

Any hints appreciated.

Alright… what a journey… :frowning:

To enable any browser that hasn’t loaded a HABpanel before, this is the process of how to make it work in OH3…

In the new browser:

a) open the OH main UI, by calling http://:8080

This should result in this:

b) click on the red ‘burger’ on the top left of the screen

… a shield with a log appears on the bottom left.

c) click this icon and log into openHAB
… the screen looks the same as under a)

d) now click on this icon image found in the top right corner.
A side menu opens, similar to this (assuming HAPpanel was installed)

e) click on HAPpanel
A screen similar to this appears

f) Click on the gear icon in the top right corner.

g) click in the area saying "restore a panel from the server
A screen similar to this appears

If you have never saved your self-designed HAPpanel to the opeHAB server, there will be no option to select a ‘Panel Configuration’ from the screen above.
Hence, you need to go back to your browser where you configured your HAPpanel and save it to the server (give it a name, etc.)
[End excusrion]

h) Tick any one of the panels you may have available (mine is called ArgyleCourt)
A screen similar to this appears

i) click OK, and select your panel.

In my case this:

We have a mountain cabin that people can rent and have created HABPanel that our guests can use to see the weather forecast, the current temperature and so on. The idea was to let the guests access the panel by scanning a QR-code on the wall. After a long battle trying to get it to work, I finally found this thread. It’s beyond my comprehension why this has to be so complicated. Why can’t a link to a panel configuration, stored on the server, just work?