When starting JBoss Tools initially I see this nice stack trace.

??$ ~/java/eclipse/jbds-12/studio/codereadystudio &
[2] 11558
[whitingjr@burtha-f31] ~ $ log4j:WARN No appenders could be found for logger (org.eclipse.jgit.internal.storage.file.FileSnapshot).
log4j:WARN Please initialize the log4j system properly.
May 28, 2020 9:52:40 AM com.redhat.microprofile.ls.MicroProfileLanguageServer initialize
INFO: Initializing MicroProfile server 0.0.6-20200415-0830 with /usr/lib/jvm/java-11-openjdk-11.0.4.11-4.fc31.x86_64
May 28, 2020 9:52:40 AM org.eclipse.lsp4j.jsonrpc.RemoteEndpoint fallbackResponseError
SEVERE: Internal error: java.lang.reflect.InvocationTargetException
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at org.eclipse.lsp4j.jsonrpc.services.GenericEndpoint.lambda$null$0(GenericEndpoint.java:67)
at org.eclipse.lsp4j.jsonrpc.services.GenericEndpoint.request(GenericEndpoint.java:120)
at org.eclipse.lsp4j.jsonrpc.RemoteEndpoint.handleRequest(RemoteEndpoint.java:261)
at org.eclipse.lsp4j.jsonrpc.RemoteEndpoint.consume(RemoteEndpoint.java:190)
at com.redhat.microprofile.ls.commons.ParentProcessWatcher.lambda$apply$0(ParentProcessWatcher.java:140)
at org.eclipse.lsp4j.jsonrpc.json.StreamMessageProducer.handleMessage(StreamMessageProducer.java:194)
at org.eclipse.lsp4j.jsonrpc.json.StreamMessageProducer.listen(StreamMessageProducer.java:94)
at org.eclipse.lsp4j.jsonrpc.json.ConcurrentMessageProcessor.run(ConcurrentMessageProcessor.java:113)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.eclipse.lsp4j.jsonrpc.services.GenericEndpoint.lambda$null$0(GenericEndpoint.java:65)
... 12 more
Caused by: java.lang.NullPointerException
at com.redhat.microprofile.ls.JavaTextDocumentService.codeLens(JavaTextDocumentService.java:154)
at com.redhat.microprofile.ls.MicroProfileTextDocumentService.codeLens(MicroProfileTextDocumentService.java:198)
... 17 more

(Red Hat CodeReady Studio:11588): Gtk-CRITICAL **: 10:00:48.705: gtk_box_gadget_distribute: assertion 'size >= 0' failed in GtkScrollbar??

I can ignore it. JBoss Tools loads and I can use it as an IDE.

$ uname -a
Linux burtha-f31 5.6.13-200.fc31.x86_64 #1 SMP Thu May 14 23:26:14 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
$ java -version
openjdk version "11.0.4" 2019-07-16
OpenJDK Runtime Environment 18.9 (build 11.0.4+11)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.4+11, mixed mode, sharing)
$