#34 jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader

[M.G]

$  java -jar '/home/m/Downloads/thingamablog-1.1b6/thingamablog.jar' 
Exception in thread "main" java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
    at net.sf.thingamablog.ClassPathHacker.addURL(Unknown Source)
    at net.sf.thingamablog.ClassPathHacker.addFile(Unknown Source)
    at net.sf.thingamablog.App.main(Unknown Source)

OS: EndeavourOS