If you get the message in the IE browser:
Just download the JAR file from server.
Start the developer mode of your browser and search for "jar" to get the filename.
In my case it was M2.JAR
Now you have to download the file with http://
Please note, that filename is CASE SENSITIVE.
To execute the java archive, JRE must be installed. I installed v8.121.
Now you can start it under Windows and Linux. Under Linux you have to mark the file as executable.