When I launch Minecraft 1.16.2 the game just crashes right after "Using default game log configuration client-1.12.xml (outputs XML)" appears in logs. Using Java 11 with OpenJ9. The only thing I did to the JVM arguments was changing -Xmx2G to -Xms4G -Xmx4G to allow for more memory. Crashed with exit code 1. 
Logs:
11:00:53.143 Preparing to launch minecraft client for 1.16.2
11:00:53.734 Checking installations.
11:00:53.735 Minecraft client 1.16.2 is ready to start.
11:00:53.735 Starting!
11:00:54.431 Using default game log configuration client-1.12.xml (outputs XML)
11:00:56.354 Exception in thread "main" java.lang.ExceptionInInitializerError at java.base/java.lang.J9VMInternals.ensureError(Unknown Source) at java.base/java.lang.J9VMInternals.recordInitializationFailure(Unknown Source) at java.base/java.lang.invoke.MethodHandle.getCPMethodHandleAt(Native Method) at java.base/java.lang.invoke.MethodHandle.getAdditionalBsmArg(Unknown Source) at java.base/java.lang.invoke.MethodHandle.resolveInvokeDynamic(Unknown Source) at hk.<clinit>(SourceFile:50) at gm.<clinit>(SourceFile:237) at vm.a(SourceFile:42) at net.minecraft.client.main.Main.main(SourceFile:137) Caused by: java.lang.NullPointerException at hk.a(SourceFile:88) at kk.a(SourceFile:20) at kk.<clinit>(SourceFile:13) ... 7 more
11:00:56.354 Process crashed with exit code 1