To reproduce, run any Swing application on MacOS with a security manager enabled. For example:

$ java -Djava.security.manager SimpleSwingApp
Exception in thread "AWT-EventQueue-0" java.lang.Error: Cannot load com.apple.laf.AquaLookAndFeel
at java.desktop/javax.swing.UIManager.initializeDefaultLAF(UIManager.java:1405)
at java.desktop/javax.swing.UIManager.initialize(UIManager.java:1516)
at java.desktop/javax.swing.UIManager.maybeInitialize(UIManager.java:1482)
at java.desktop/javax.swing.UIManager.getUI(UIManager.java:1055)
at java.desktop/javax.swing.JPanel.updateUI(JPanel.java:126)
at java.desktop/javax.swing.JPanel.<init>(JPanel.java:86)
at java.desktop/javax.swing.JPanel.<init>(JPanel.java:109)
at java.desktop/javax.swing.JPanel.<init>(JPanel.java:117)
at java.desktop/javax.swing.JRootPane.createGlassPane(JRootPane.java:519)
at java.desktop/javax.swing.JRootPane.<init>(JRootPane.java:346)
at java.desktop/javax.swing.JFrame.createRootPane(JFrame.java:279)
at java.desktop/javax.swing.JFrame.frameInit(JFrame.java:258)
at java.desktop/javax.swing.JFrame.<init>(JFrame.java:225)
at SimpleSwingApp.<init>(SimpleSwingApp.java:12)
at SimpleSwingApp.lambda$main$1(SimpleSwingApp.java:32)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:759)
at java.desktop/java.awt.EventQueue.access$500(EventQueue.java:97)
at java.desktop/java.awt.EventQueue$3.run(EventQueue.java:712)
at java.desktop/java.awt.EventQueue$3.run(EventQueue.java:706)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:79)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:729)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:199)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90