java is not on the classpath message in a non-Android Gradle project

The error is:
.java is not on the classpath of project xxxx, only syntax errors are reported

Environment

• Operating System: MacOs, Catalina 10.15.7
• JDK version:

openjdk version "11.0.9" 2020-10-20 LTS
OpenJDK Runtime Environment Zulu11.43+21-CA (build 11.0.9+11-LTS)
OpenJDK 64-Bit Server VM Zulu11.43+21-CA (build 11.0.9+11-LTS, mixed mode)

• Visual Studio Code version: 1.55.2
• Java extension version: 0.76.0

Steps To Reproduce

1. Import Gradle project
2. Open .java file

Here are some other messages that I get:

Could not run phased build action using connection to Gradle distribution 'https://services.gradle.org/distributions/gradle-6.4.1-all.zip'.
The newly created daemon process has a different context than expected.
It won't be possible to reconnect to this daemon. Context mismatch:
Java home is different.
Wanted: DefaultDaemonContext[uid=null,javaHome=/nix/store/g4lwpql3c2lyw7m04wxbrx72x9kh0w9j-zulu11.43.21-ca-jdk11.0.9,daemonRegistryDir=/Users/xxxxx/.gradle/daemon,pid=49638,idleTimeout=null,priority=NORMAL,daemonOpts=--add-opens,java.base/java.util=ALL-UNNAMED,--add-opens,java.base/java.lang=ALL-UNNAMED,--add-opens,java.base/java.lang.invoke=ALL-UNNAMED,--add-opens,java.prefs/java.util.prefs=ALL-UNNAMED,-XX:MaxMetaspaceSize=256m,-XX:+HeapDumpOnOutOfMemoryError,-Xms256m,-Xmx512m,-Dfile.encoding=utf8,-Duser.country=GB,-Duser.language=en,-Duser.variant]
Actual: DefaultDaemonContext[uid=415ee891-9ddf-491a-a2cb-c7cee384bfab,javaHome=/nix/store/g4lwpql3c2lyw7m04wxbrx72x9kh0w9j-zulu11.43.21-ca-jdk11.0.9/zulu-11.jdk/Contents/Home,daemonRegistryDir=/Users/xxxxx/.gradle/daemon,pid=49652,idleTimeout=10800000,priority=NORMAL,daemonOpts=--add-opens,java.base/java.util=ALL-UNNAMED,--add-opens,java.base/java.lang=ALL-UNNAMED,--add-opens,java.base/java.lang.invoke=ALL-UNNAMED,--add-opens,java.prefs/java.util.prefs=ALL-UNNAMED,-XX:MaxMetaspaceSize=256m,-XX:+HeapDumpOnOutOfMemoryError,-Xms256m,-Xmx512m,-Dfile.encoding=utf8,-Duser.country=GB,-Duser.language=en,-Duser.variant]

Additional Informations

I am also trying to get Emacs work with this project. I have lots of NullPointerExceptions from the plugins in the lsp-log there.
I've read that Gradle projects for Android are not supported. Well, this one is not for Android.
Here is what I put in build.gradle:

plugins {
id 'java'
id 'eclipse'
id 'idea'
...

I also put this (to have the classes copied in bin and not only in the build directory:

task copyBuildToBin(type: Copy) {
from 'build/classes/java/'
from 'build/resources/'
into 'bin/'
}

Commencez par reproduire l’importation Gradle de l’issue, ouvrir un fichier .java dans l’extension Java de VS Code et examiner le build.gradle du projet. Comparez l’erreur de classpath avec le décalage de Java-home signalé pour le daemon Gradle et les NullPointerExceptions du serveur de langage. Le travail est terminé lorsqu’un projet Gradle non Android s’importe sans l’avertissement de classpath et que les fichiers Java sont entièrement pris en charge, plutôt qu’avec la syntaxe uniquement.