Downloaded .jar runs into Java exception with latest updates

[olakend]

Hi,

I downloaded from the official page the Linux version of the launcher. I just installed the latest jdk (java-latest-openjdk-devel) and I have all the available updates installed on my Fedora 30 system.

When running the file with the following command (without and with sudo):

java -jar TechnicLauncher.jar

I get the following java exception:

Exception in thread "main" java.awt.HeadlessException
	at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:204)
	at java.awt.Window.<init>(Window.java:536)
	at java.awt.Frame.<init>(Frame.java:420)
	at java.awt.Frame.<init>(Frame.java:385)
	at javax.swing.JFrame.<init>(JFrame.java:189)
	at net.technicpack.ui.controls.DraggableFrame.<init>(DraggableFrame.java:32)
	at net.technicpack.launcher.ui.InstallerFrame.<init>(InstallerFrame.java:79)
	at net.technicpack.launcher.LauncherMain.main(LauncherMain.java:167)

I hope that this can work, bacause I could not find any better launcher alternatives with automatic modpack install.

[olakend]

After a bit of research I found out, that the Launcher is not working with Java 9+.

The solution was to remove the latest version and install java-1.8.0-openjdk.

If there is an admin reading this, I would suggest, to add a large note to the download page, that describes the system requirements.