ArrayIndexOutOfBoundsException during "Find Usages" operation

I'm using Netbeans 11 vc4 on Java 8 multi-project (on Windows).  I ran "Find Usages" on a method and got the exception below.  After this exception, the find results were empty, despite there being callers of the method within the search scope.

I have spent a ton of time working with the same project using Netbeans 10, and running "Find Usages" frequently.  I never got this exception there before, and Find Usages has been totally robust until now.  So it seems this is likely a new bug in Netbeans 11.

I cannot provide the gigantic multi-project where this problem is reproducible.  I could try to reduce it down to a minimal testcase and then obfuscate the code, if you need an example project to reproduce this issue or to test the fix.

Thanks!

java.lang.ArrayIndexOutOfBoundsException
at java.lang.System.arraycopy(Native Method)
at org.netbeans.modules.refactoring.java.ui.tree.FolderTreeElement.getSourceGroup(FolderTreeElement.java:119)
at org.netbeans.modules.refactoring.java.ui.tree.TreeElementFactoryImpl.getTreeElement(TreeElementFactoryImpl.java:55)
at org.netbeans.modules.refactoring.spi.ui.TreeElementFactory.getTreeElement(TreeElementFactory.java:44)
at org.netbeans.modules.refactoring.java.ui.tree.FileTreeElement.getParent(FileTreeElement.java:75)
at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.createNode(RefactoringPanel.java:488)
at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.createNode(RefactoringPanel.java:493)
at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.createNode(RefactoringPanel.java:493)
at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.access$1100(RefactoringPanel.java:80)
at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel$3.run(RefactoringPanel.java:765)
at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1418)
at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:45)
at org.openide.util.lookup.Lookups.executeWith(Lookups.java:278)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)