[SOLVED] SikuliX IDE is stuck starting up with message: SikuliX-IDE 2.0.4 is starting on Java 15

SikuliX IDE is stuck starting up with message: SikuliX-IDE 2.0.4 is starting on Java 15

Machine: MacBook Pro running macOS Catalina V10.15.7
Downloaded Java JDK 15 from: https://jdk.java.net/15/
Put the jdk folder in /Library/Java/JavaVirtualMachines/ (I had to manually create the JavaVirtualMachines folder as I'd previously deleted it whilst uninstalling a previous java installation)
Downloaded SikuliX version 2.0.4 from https://raiman.github.io/SikuliX1/downloads.html
Downloaded Jython 2.7.1 from https://github.com/RaiMan/SikuliX1/wiki/How-to-make-Jython-ready-in-the-IDE
Put the Jython jar in the same directory as the Sikuli jar

When I run SikuliX IDE (either double clicking the .jar file or running java -jar command in the terminal), SikuliX starts but gets stuck with this pop up on screen: "SikuliX-IDE 2.0.4 is starting on Java 15"

When I run the debug command "java -jar sikulixide-2.0.4.jar -v" this it the output (I can't interpret anything wrong from this):

java -jar sikulixide-2.0.4.jar -v
[DEBUG]startUp: IDE: Running: /Users/nick/Documents/Year 4/Final Year Project/sikulixide-2.0.4.jar
[DEBUG]startUp: IDE: AppData: /Users/nick/Library/Application Support/Sikulix
[DEBUG]startUp: IDE: starting with classpath: sikulixide-2.0.4.jar ...
[DEBUG]startUp: IDE: no extensions.txt nor valid content
[DEBUG]startUp: IDE: adding extension file: /Users/nick/Library/Application Support/Sikulix/Extensions/jython-standalone-2.7.1.jar
[576 debug] RunTime:temp folder ok: /var/folders/_4/gdj7lxvn47q6bvm5pzpj6xdr0000gn/T/Sikulix_2010589482
Options: *** options dump
Options: testing = 
Options: OptionsFile = /Users/nick/Library/Application Support/Sikulix/SikulixStore/SikulixOptions.txt
Options: *** options dump end
***** show environment for 2.0.4-2020-03-14_08:01 API
user.home: /Users/nick
user.dir (work dir): /Users/nick/Documents/Year 4/Final Year Project
user.name: nick
java.io.tmpdir: /var/folders/_4/gdj7lxvn47q6bvm5pzpj6xdr0000gn/T
running 64Bit(x86_64) on m (10.15.7) from a jar
java 15 version 15 vm 15.0.1+9-18 class 59.0 arch 64
app data folder: /Users/nick/Library/Application Support/Sikulix
executing jar: /Users/nick/Documents/Year%204/Final%20Year%20Project/sikulixide-2.0.4.jar
*** classpath dump sikulix
  0: sikulixide-2.0.4.jar
*** classpath dump end
***** show environment end
[DEBUG]startUp: IDE: *********************** leaving start
[65 debug] Sikulix: starting IDE
[178 debug] RunTime:temp folder ok: /var/folders/_4/gdj7lxvn47q6bvm5pzpj6xdr0000gn/T/Sikulix_2118090038
Options: *** options dump
Options: testing = 
Options: OptionsFile = /Users/nick/Library/Application Support/Sikulix/SikulixStore/SikulixOptions.txt
Options: *** options dump end
***** show environment for 2.0.4-2020-03-14_08:01 IDE
user.home: /Users/nick
user.dir (work dir): /Users/nick/Documents/Year 4/Final Year Project
user.name: nick
java.io.tmpdir: /var/folders/_4/gdj7lxvn47q6bvm5pzpj6xdr0000gn/T
running 64Bit(x86_64) on m (10.15.7) from a jar
java 15 version 15 vm 15.0.1+9-18 class 59.0 arch 64
app data folder: /Users/nick/Library/Application Support/Sikulix
executing jar: /Users/nick/Documents/Year%204/Final%20Year%20Project/sikulixide-2.0.4.jar
*** classpath dump sikulix
  0: /Users/nick/Documents/Year 4/Final Year Project/sikulixide-2.0.4.jar
  1: /Users/nick/Library/Application Support/Sikulix/Extensions/jython-standalone-2.7.1.jar
  2: sikulixide-2.0.4.jar
*** classpath dump end
***** show environment end
[355 debug] IDE: running with Locale: en_US
[DEBUG]startUp: IDE: --- Sikuli parameters ---
[DEBUG]startUp: IDE: 1: -v
[367 debug] HotkeyManager: add Capture Hotkey: ⌘+⇧ 2 (50, 5)
[546 debug] HotkeyManager: add Abort Hotkey: ⌘+⇧ C (67, 5)
[553 debug] IDE: Init ScriptingSupport
[555 debug] IDESupport: enter
[1212 debug] Runner: added: Text [txt] text/text
[1213 debug] Runner: added: Sikulix [] directory/sikulix
[1213 debug] Runner: added: AppleScript [script] text/applescript
[1214 debug] Runner: added: SikulixJar [jar] text/jar
[1224 debug] Runner: added: Jython [py] text/jython

I've also tried creating a SikulixDebug.txt file in my home directory as suggested in http://sikulix.com/quickstart/ however this did not yield any results, no output was recorded to the text file. (also tried putting that text file in the same directory as the jar)

Let me know if you have any suggestions!

Solution

RaiMan from SikuliX: Java 15 not supported yet. Use Java 11. Preferably from here: https://adoptopenjdk.net/