Java 13 seemed to be the problem. This tells how to determine what versions you have installed, and how to choose one: https://stackoverflow.com/questions/21964709/how-to-set-or-change-the-default-java-jdk-version-on-macos
Choosing Java 1.8 made everything better. --Brian On Monday, September 20, 2021 at 4:59:44 PM UTC-5 Brian Larson wrote: > Running mmj2 on MacOS 10.15.7 with Java 13.0.2, misbehaves and spews error > messages like the one below to the console/terminal. > > However, on Ubuntu with Java 1.8.0_191, it works swimmingly. > > Users experiencing confounding behavior should check what version of Java > is installed. > > > --Brian > > > java.lang.ClassCastException: class > javax.swing.text.AbstractDocument$DefaultDocumentEventUndoableWrapper > cannot be cast to class > javax.swing.text.AbstractDocument$DefaultDocumentEvent > (javax.swing.text.AbstractDocument$DefaultDocumentEventUndoableWrapper and > javax.swing.text.AbstractDocument$DefaultDocumentEvent are in module > java.desktop of loader 'bootstrap') > > at > mmj.pa.CompoundUndoManager.undoableEditHappened(CompoundUndoManager.java:110) > > at > java.desktop/javax.swing.text.AbstractDocument.fireUndoableEditUpdate(AbstractDocument.java:293) > > at > java.desktop/javax.swing.text.DefaultStyledDocument.setCharacterAttributes(DefaultStyledDocument.java:530) > > at mmj.pa.ColorThread.processEvent(ColorThread.java:266) > > at mmj.pa.ColorThread.run(ColorThread.java:170) > -- You received this message because you are subscribed to the Google Groups "Metamath" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/metamath/b78ba53a-f118-4148-a305-95c9b623d89bn%40googlegroups.com.
