I am having a similar issue on Fedora 27.

I installed Oracle Java, configured alternatives to point to Oracle java, and was able to get past the error in the first post, but the window comes up incredibly small and unable to resize, probably 20 pixels by 70 pixels, mostly contributed by the window decorations. Have you seen this one before?

I have not. Are you on a HiDPI (hi resolution) monitor?

Yes: I have three monitors, one is 4k @ 15 inches, the others are 1080p at reasonable DPI. However, if I disable the 4k monitor the same things happen (Unfortunately I can't fully unplug it, since it's the laptop display...)

Same if I disable all but one of the 1080p monitors

Try disabling the high dpi scaling. or execute the client with --force-device-scale-factor=1

Thanks for the reply!

The client does come up normally if I totally disable desktop scaling. With scaling enabled the --force-device-scale-factor=1 and desktop scaling enabled I don't see any difference.

Since this worked, I tried launching the game in a Xeypher session. That also works as far as seeing the launcher, but I get "Exception in thread "main" java.lang.NoClassDefFoundError: sun/audio/AudioPlayer" when I try to play the game.

(Disabling the display scaling is not a great solution for me because everything is hilariously large, but I'm really enjoying playing on Android in any case 🙂 )

Try disabling the high dpi scaling. or execute the client with --force-device-scale-factor=1

Thanks for the reply!

The client does come up normally if I totally disable desktop scaling. With scaling enabled the --force-device-scale-factor=1 and desktop scaling enabled I don't see any difference.

Since this worked, I tried launching the game in a Xeypher session. That also works as far as seeing the launcher, but I get "Exception in thread "main" java.lang.NoClassDefFoundError: sun/audio/AudioPlayer" when I try to play the game.

(Disabling the display scaling is not a great solution for me because everything is hilariously large, but I'm really enjoying playing on Android in any case 🙂 )

You are getting that error because you have not set your defaults to your Java 8 installation. Java 9 and 10 have rewritten the way Java handles audio, so it "breaks" functionality. To set your default java version prior to launch, please use the following code:

sudo update-alternatives --config java

Remember to ensure you have oracle java 8 installed.

Thanks,
Pyru

Oh gosh. You're totally right, I wasn't paying attention when I installed Oracle Java. That works!

For reference, the setup for me is now:

Xephyr -ac -noreset -screen 800x600 :9 & DISPLAY=:9 java -jar ./RSCE_Launcher.jar

Which launches a nested X session (Xephyr) then launches the client in it