refactoring rename throws exceptions, inviting me to report it

An error occurred during parsing of '/home/hom/sebi/alda/trunk/30_practical/sorting/solution/sortingservice/src/test/java/teachertests/InsertionTest.java'. Please report a bug against java/source and attach dump file '/home/hom/.netbeans/11.2-beta3/var/log/InsertionTest.dump'.
An error occurred during parsing of '/home/hom/sebi/alda/trunk/30_practical/sorting/solution/sortingservice/src/test/java/teachertests/InsertionTest.java'. Please report a bug against java/source and attach dump file '/home/hom/.netbeans/11.2-beta3/var/log/InsertionTest.dump'.
Caused: java.lang.AssertionError
at com.sun.tools.javac.util.Assert.error(Assert.java:155)
at com.sun.tools.javac.util.Assert.checkNonNull(Assert.java:62)
at com.sun.tools.javac.comp.Modules.setCompilationUnitModules(Modules.java:559)
at com.sun.tools.javac.comp.Modules.enter(Modules.java:287)
at com.sun.tools.javac.comp.Modules.enter(Modules.java:268)
at com.sun.tools.javac.comp.Modules.initModules(Modules.java:259)
at com.sun.tools.javac.main.JavaCompiler.initModules(JavaCompiler.java:1126)
at com.sun.tools.javac.api.JavacTaskImpl.enter(JavacTaskImpl.java:393)
at com.sun.tools.javac.api.JavacTaskImpl.enter(JavacTaskImpl.java:327)
at org.netbeans.modules.java.source.parsing.JavacParser.moveToPhase(JavacParser.java:660)
at org.netbeans.modules.java.source.parsing.CompilationInfoImpl.toPhase(CompilationInfoImpl.java:361)
at org.netbeans.api.java.source.CompilationController.toPhase(CompilationController.java:84)
at org.netbeans.api.java.source.WorkingCopy.toPhase(WorkingCopy.java:193)
at org.netbeans.modules.refactoring.java.spi.RefactoringVisitor.setWorkingCopy(RefactoringVisitor.java:110)
at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$TransformTask.run(JavaRefactoringPlugin.java:425)
at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$TransformTask.run(JavaRefactoringPlugin.java:408)
at org.netbeans.api.java.source.JavaSource$1.run(JavaSource.java:673)
at org.netbeans.api.java.source.JavaSource$1.run(JavaSource.java:663)
at org.netbeans.api.java.source.JavaSource$MultiTask.run(JavaSource.java:502)
at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:586)
at org.netbeans.modules.parsing.api.ParserManager$MultiUserTaskAction.run(ParserManager.java:166)
at org.netbeans.modules.parsing.api.ParserManager$MultiUserTaskAction.run(ParserManager.java:138)
at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:181)
at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:178)
at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:153)
at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:335)
at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:118)
at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:67)
at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:178)
at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:83)
at org.netbeans.api.java.source.JavaSource.runUserActionTaskImpl(JavaSource.java:452)
at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:423)
at org.netbeans.api.java.source.JavaSource.runModificationTask(JavaSource.java:684)
at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin.processFiles(JavaRefactoringPlugin.java:317)
at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin.processFiles(JavaRefactoringPlugin.java:263)
at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin.processFiles(JavaRefactoringPlugin.java:245)
at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin.createAndAddElements(JavaRefactoringPlugin.java:326)
at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin.prepare(RenameRefactoringPlugin.java:626)
[catch] at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare2(AbstractRefactoring.java:417)
at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:401)
at org.netbeans.modules.refactoring.api.AbstractRefactoring.prepare(AbstractRefactoring.java:212)
at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$Prepare.run(ParametersPanel.java:1063)
at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1418)
at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:45)
at org.openide.util.lookup.Lookups.executeWith(Lookups.java:278)
at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)