Hi, 
So it took me a while to figure out how to make it work so i tought i share what i found with the community. 

Java is no longer supported in firefox and chrominium for a while now. The litterature you find on the internet is to install IcedTea on linux but all the repo are now empty since it's no longer supported. 

What you need to do is to download it via terminal with this command

 

sudo apt install icedtea-netx

Then, download the admin consoli by entering your ISY994 ip adresse. After this step go to the downloaded file folder and run

javaws admin.jnlp 

You now have the admin consol running on the latest linux.

 

For me, i am running on LUBUNTU in october 2020

I'm running Ubuntu 20.04 LTS. A few more tidbits should they prove helpful.

To download the jnlp file, direct Firefox to your_ISY_address/admin.jnlp as other means don't work (your_ISY_address as in 192.168.x.xx).

IcedTea is also available as a snap (search for "java" in Ubuntu Software).

I also installed Java (OpenJDK 14), but I don't think that's necessary.

Open Terminal and CD to Downloads (assuming admin.jnlp was saved in the default location). Then enter

javaws admin.jnlp

Ignore the desktop shortcut, as it just downloads another copy of the jnlp script.

I have a 4K TV as a monitor. Not only is the font minuscule but the logon window cannot be accessed. Once I adjusted the display resolution in Settings to 1280x720 I could add devices and modify programs, but it wasn't pretty. I'm sure there is a way to add a launch script that could include display variables, but I was just happy to add a device while my Windows machine is down.