Imagegen fails on Java 11

[Reportage]

Error 500: /imagegen/id java.lang.NoClassDefFoundError: Could not initialize class java.awt.GraphicsEnvironment$LocalGE

java.lang.NoClassDefFoundError: Could not initialize class java.awt.GraphicsEnvironment$LocalGE
     at java.desktop/java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:129)
     at java.desktop/java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1181)
     at com.docuverse.identicon.NineBlockIdenticonRenderer2.renderQuilt(NineBlockIdenticonRenderer2.java:225)
     at com.docuverse.identicon.NineBlockIdenticonRenderer2.render(NineBlockIdenticonRenderer2.java:175)
     at net.i2p.imagegen.IdenticonServlet.doGet(IdenticonServlet.java:149)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
     at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
     at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)
     at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
     at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)
     at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
     at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
     at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
     at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
     at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
     at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
     at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215)
     at org.eclipse.jetty.servlets.gzip.GzipHandler.handle(GzipHandler.java:479)
     at net.i2p.router.web.HostCheckHandler.handle(HostCheckHandler.java:120)
     at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
     at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
     at org.eclipse.jetty.server.Server.handle(Server.java:499)
     at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
     at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:258)
     at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
     at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
     at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
     at java.base/java.lang.Thread.run(Thread.java:834)

[zzz]

Full version info please.
Can't reproduce, works for me here:

Java version:	Oracle Corporation 11.0.3 (OpenJDK Runtime Environment 11.0.3+7-Ubuntu-1ubuntu218.10.1)
Wrapper version:	3.5.39
Server version:	9.2.25.v20180606
Servlet version:	Jasper JSP 2.3 Engine
JSTL version:	standard-taglib 1.2.0
Platform:	Linux amd64 4.18.0-18-generic
Processor:	Bulldozer (bulldozer)
JBigI status:	Locally optimized library libjbigi-linux-bulldozer_64.so loaded from file
GMP version:	6.0.0
JBigI version:	3
JCpuId version:	3
Encoding:	UTF-8
Charset:	UTF-8
Built By:	zzz

[Reportage]

I2P:		0.9.40-3+ Wrapper: 3.5.34  Built by: dr|z3d
Platform:	Linux amd64 4.15.0-47-generic
Processor:	corei  Intel model 79  [Jcpuid version: 3]
Java:		Oracle Corporation 11.0.3 (OpenJDK Runtime Environment 11.0.3+7-Ubuntu-1ubuntu218.04.1)
Jetty:		9.2.28.v20190418 Servlet: Jasper JSP 2.3 Engine
JBigI:		Locally optimized library libjbigi-linux-corei_64.so loaded from file [version: 3] GMP: 6.0.0
JSTL:		standard-taglib 1.2.0 Encoding: UTF-8 Charset: UTF-8

[zzz]

error caught in dd4bb4d65f0f60090b25e8419404a9d8e087acdc 0.9.40-13-rc but I can't do anything about a class not found anyway, and can't reproduce it here. Our installs look similar but something is obviously different about yours. The error will be caught and the browser will get a 403, that's the best I can do.