java.lang.AssertionError: Should be a folder: C:\Users\Mark\Documents\NetBeansProjects\JavaApplication45\build\classes@71846258:1f931ac data: true
   at org.netbeans.modules.masterfs.watcher.Watcher$Ext.register(Watcher.java:225)
   at org.netbeans.modules.masterfs.watcher.Watcher.register(Watcher.java:119)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj.addFileChangeListener(BaseFileObj.java:501)
   at org.netbeans.modules.java.source.usages.fcs.FileChangeSupport$Holder.locateCurrent(FileChangeSupport.java:165)
   at org.netbeans.modules.java.source.usages.fcs.FileChangeSupport$Holder.someChange(FileChangeSupport.java:184)
   at org.netbeans.modules.java.source.usages.fcs.FileChangeSupport$Holder.fileFolderCreated(FileChangeSupport.java:217)
   at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEventImpl(FCLSupport.java:142)
   at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEvent(FCLSupport.java:128)
   at org.openide.filesystems.FCLSupport.dispatchEvent(FCLSupport.java:105)
   at org.openide.filesystems.FileObject$ED.dispatch(FileObject.java:1165)
   at org.openide.filesystems.FileSystem$EventDispatcher.run(FileSystem.java:956)
   at org.openide.filesystems.EventControl.dispatchEvent(EventControl.java:84)
   at org.openide.filesystems.FileSystem.dispatchEvent(FileSystem.java:601)
   at org.openide.filesystems.FileObject.dispatchEvent(FileObject.java:548)
   at org.openide.filesystems.FileObject.fireFileFolderCreatedEvent(FileObject.java:508)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj.fireFileFolderCreatedEvent(BaseFileObj.java:635)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FolderObj.refreshImpl(FolderObj.java:477)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj.refresh(BaseFileObj.java:801)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FolderObj.refresh(FolderObj.java:539)
   at org.openide.filesystems.FileObject.refresh(FileObject.java:1078)
   at org.netbeans.modules.masterfs.watcher.Watcher$1.run(Watcher.java:370)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1411)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1991)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError: Should be a folder: C:\Users\Mark\Documents\NetBeansProjects\JavaApplication45\build\classes@71846258:1f931ac data: true
   at org.openide.util.RequestProcessor$Task.schedule(RequestProcessor.java:1452)
   at org.netbeans.modules.masterfs.watcher.Watcher.enqueue(Watcher.java:383)
   at org.netbeans.modules.masterfs.watcher.Watcher.access$200(Watcher.java:72)
   at org.netbeans.modules.masterfs.watcher.Watcher$Ext.run(Watcher.java:324)
   at java.lang.Thread.run(Thread.java:722)