I have a clean install of Ubuntu 20.04.
I installed the “stable” openhab repositories and install using apt-get install openhab2.
Everything works ok except the log viewer. When I click on it there is a slight pause and then it gives me a refused to connect error.
I don’t know what the openhab2-addons package contains but I installed that too in case it was required but it still gives the refused to connect error.