Cannot open the Model Page of the new MainUI in openHAB3

I have problems opening the model page in the administration area of the new main UI of openHAB 3.0 stable version. The cursor is active displaying “Loading…” for minutes without any progress. All other pages of the main UI are reactive and information is displayed shortly after a click.

This happens with Firefox 84.0.2 and with MS Edge 87.0.

The logfiles “openhab.log” and “events.log” don’t contain any entry related to this issue.

CPU usage of my RaspberryPi 3B is between 2,5% and 12,5% (using the command “top”), so there shouldn’t exist a hardware resource problem.

How do I trace this issue effectively?

I just found out, that I can open the model page again after closing the current user session and logging in again.
Anyway I have no idea, how to recreate the situation and give further information to fix it.

Report errors in the Console tab of the browser developer tools (F12).

This is the console output of the developer tools of Firefox after having clicked to open the model page

In contrast, this is the output after having clicked to open the model page, when the model page opens:

i get something similar. Main UI becomes unresponsive sometimes after making config changes.
So i have to close that window open a new one and open mainUI again and it works.

Also, my model tab would crash like you have mentioned if i accidentally make an item/equipment, have a parent group of itself.

Hu, so there’s an error, but the message doesn’t help…
Any network requests in error?

I am not experienced in debbuging client side JavaScript code. Anyway I toggled the switch in the debugger of Firefox to stop the application in case of an exception. This is the information, that I could gather then:


Please give further advice, if you need more details.


can I ask you if your items page also loads longer? I have a similar issue posted here:

Another user suspected that it might have to do with the authentication, which would support that the logging out/in fixes it.
I have always restarted openhab to fix it, I still have to try the user session trick!

I have tested for about 15 minutes. Having currently 525 items the items page always loads in about 6 seconds (Firefox + Raspberrypi 3b + Zulu JDK). I cannot confirm, that the load time of the items page degrades after some time of using the interface. This remains true, when it isn’t possible to load the model page at all caused by the problem discussed in this thread.