Fatal Error: Unable to find package java.lang in classpath or bootclasspath

I can't use Neatbeans at all because of this fatal error. Also reported here https://askubuntu.com/questions/1166639/cant-using-netbeans-10-0-after-installing-from-repository-on-ubuntu-18-04

Fatal Error: Unable to find package java.lang in classpath or bootclasspath.

See the attached screenshot.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: netbeans 10.0-3ubuntu3
ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30
Uname: Linux 5.4.0-29-generic x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Mon May 18 18:33:07 2020
InstallationDate: Installed on 2020-04-26 (22 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: netbeans
UpgradeStatus: No upgrade log present (probably fresh install)