Unhandled Eventloop Exception (MacOS 14.3.1)

Windowbuilder was working with this window until the last batch of changes I made to it. I get no warnings or compile errors in my project, the Windowbuilder Design tap just show up empty.

My project is opensource and after doing some digging, the error appears in this (small) commit:
https://github.com/obscurestar/choordinates/commit/10c3ec90987c35c822aa5a1f17a3f8c548a0cc9e#diff-24bc5d99104ec827f095ecd47ae668ae04b178c150fd5750a9c31aa8502f89e9L136

and appears to be related to the creation of a new public constructor in the unrelated 'ToneChord' class. (Even with the removal of 'foo' object)

Below is the stack trace from the General Error log stack trace when I click the design tab for the 'Choordinates' window in my project.

java.lang.NullPointerException: String is null
at java.desktop/sun.java2d.SunGraphics2D.drawString(SunGraphics2D.java:2925)
at choordinates.FretPanel.paintComponent(FretPanel.java:273)
at java.desktop/javax.swing.JComponent.printComponent(JComponent.java:1292)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1132)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:965)
at java.desktop/javax.swing.JComponent.printChildren(JComponent.java:1305)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1140)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:965)
at java.desktop/javax.swing.JComponent.printChildren(JComponent.java:1305)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1140)
at java.desktop/javax.swing.JLayeredPane.paint(JLayeredPane.java:586)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:965)
at java.desktop/javax.swing.JComponent.printChildren(JComponent.java:1305)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1140)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/java.awt.GraphicsCallback$PrintCallback.run(GraphicsCallback.java:50)
at java.desktop/sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:75)
at java.desktop/sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:112)
at java.desktop/java.awt.Container.print(Container.java:2060)
at java.desktop/sun.lwawt.LWComponentPeer.print(LWComponentPeer.java:807)
at java.desktop/sun.lwawt.LWContainerPeer.print(LWContainerPeer.java:276)
at java.desktop/java.awt.GraphicsCallback$PeerPrintCallback.run(GraphicsCallback.java:103)
at java.desktop/sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:75)
at java.desktop/java.awt.Component.printAll(Component.java:3534)
at org.eclipse.wb.internal.swing.utils.SwingScreenshotMaker.makeShots(SwingScreenshotMaker.java:146)
at org.eclipse.wb.internal.swing.model.component.ComponentInfo.refresh_fetch(ComponentInfo.java:156)
at org.eclipse.wb.internal.swing.model.component.ComponentInfo.refresh_fetch(ComponentInfo.java:140)
at org.eclipse.wb.internal.swing.model.component.ContainerInfo.refresh_fetch(ContainerInfo.java:258)
at org.eclipse.wb.core.model.ObjectInfo.lambda$6(ObjectInfo.java:481)
at org.eclipse.wb.internal.core.utils.execution.ExecutionUtils.runDesignTime(ExecutionUtils.java:147)
at org.eclipse.wb.core.model.ObjectInfo.lambda$5(ObjectInfo.java:480)
at org.eclipse.wb.internal.swing.utils.SwingUtils$2.run(SwingUtils.java:78)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
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)

打开 Choordinates 窗口的 WindowBuilder Design 选项卡以重现故障，然后检查第 273 行的 FretPanel.java，并比较链接的提交前后的行为。跟踪 drawString 堆栈跟踪所报告的 null 值，并确定新的 ToneChord 构造函数为何会触发该问题。设计选项卡能够在没有未处理异常的情况下渲染即表示完成。