Newer versions of libgtk-3-0 break JavaFX on linux

[elevans]

On some linux systems (I'm on Ubuntu 24.04 LTS) newer versions of libgtk-3-0 (or perhaps libgtk-4-1) introduce breaking changes for JavaFX. With the current bundled version of Java 8 with Fiji, zulu8.60.0.21, FLIMJ will fail to open with the following exception:

(Fiji Is Just) ImageJ 2.14.0/1.54f; Java 1.8.0_322 [64-bit]; Linux 6.8.0-49-generic; 410MB of 19119MB (2%)
 
java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.RuntimeException: Module threw exception
	at net.imagej.legacy.LegacyService.runLegacyCompatibleCommand(LegacyService.java:308)
	at net.imagej.legacy.DefaultLegacyHooks.interceptRunPlugIn(DefaultLegacyHooks.java:166)
	at ij.IJ.runPlugIn(IJ.java)
	at ij.Executer.runCommand(Executer.java:152)
	at ij.Executer.run(Executer.java:70)
	at java.lang.Thread.run(Thread.java:750)
Caused by: java.util.concurrent.ExecutionException: java.lang.RuntimeException: Module threw exception
	at java.util.concurrent.FutureTask.report(FutureTask.java:122)
	at java.util.concurrent.FutureTask.get(FutureTask.java:192)
	at net.imagej.legacy.LegacyService.runLegacyCompatibleCommand(LegacyService.java:304)
	... 5 more
Caused by: java.lang.RuntimeException: Module threw exception
	at org.scijava.module.ModuleRunner.call(ModuleRunner.java:128)
	at org.scijava.module.ModuleRunner.call(ModuleRunner.java:64)
	at org.scijava.thread.DefaultThreadService.lambda$wrap$2(DefaultThreadService.java:247)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	... 1 more
Caused by: java.lang.UnsupportedOperationException: Internal Error
	at com.sun.glass.ui.gtk.GtkApplication.lambda$new$5(GtkApplication.java:158)
	at java.security.AccessController.doPrivileged(Native Method)
	at com.sun.glass.ui.gtk.GtkApplication.<init>(GtkApplication.java:140)
	at com.sun.glass.ui.gtk.GtkPlatformFactory.createApplication(GtkPlatformFactory.java:41)
	at com.sun.glass.ui.Application.run(Application.java:147)
	at com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:279)
	at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:211)
	at javafx.embed.swing.JFXPanel.initFx(JFXPanel.java:249)
	at javafx.embed.swing.JFXPanel.<init>(JFXPanel.java:264)
	at flimlib.flimj.ui.FLIMJCommand.run(FLIMJCommand.java:71)
	at org.scijava.command.CommandModule.run(CommandModule.java:196)
	at org.scijava.module.ModuleRunner.run(ModuleRunner.java:165)
	at org.scijava.module.ModuleRunner.call(ModuleRunner.java:125)
	... 6 more

There are two workarounds you can use to get this working:

1. Downgrade your version of libgtk-3-0 or find a computer with an older version of Ubuntu. We found that Ubuntu 22.04.5 LTS was able to launch FLIMJ while 24.04 LTS did not. I didn't specifically test downgrading my libgtk-3-0 but it seems at least version 3.24.33-1ubuntu2.2 works and version 3.24.38-5ubuntu1 does not.
2. Update to the latest zulu JDK+FX (download the JDK+FX zulu Java 8 package and replace the java in your Fiji.app/java folder) and run Fiji with the -Djavafx.allowjs=true flag. Like so:

$ ./ImageJ-linux64 -Djavafx.allowjs=true

Thanks @ctrueden for helping figure out what was going on here!