java.lang.IllegalArgumentException: C:\Users\alan\Documents\NetBeansProjects\SkiInstructorClients\src\skiinstructorclients\Client.java is not inside C:\Users\alan\Documents\NetBeansProjects\SkiInstructorClients\src
        at org.netbeans.spi.project.support.ant.SourcesHelper$SourceRoot$Group.contains(SourcesHelper.java:198)
        at org.netbeans.spi.java.project.support.ui.PackageViewChildren$NoFoldersDataFilter.acceptFileObject(PackageViewChildren.java:1221)
        at org.openide.loaders.FolderChildren$1R.run(FolderChildren.java:155)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.IllegalArgumentException: C:\Users\alan\Documents\NetBeansProjects\SkiInstructorClients\src\skiinstructorclients\Client.java is not inside C:\Users\alan\Documents\NetBeansProjects\SkiInstructorClients\src
        at org.openide.util.RequestProcessor.post(RequestProcessor.java:292)
        at org.openide.loaders.FolderChildren.refreshChildren(FolderChildren.java:186)
        at org.openide.loaders.FolderChildren.propertyChange(FolderChildren.java:122)
        at org.openide.util.WeakListenerImpl$PropertyChange.propertyChange(WeakListenerImpl.java:188)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
        at org.openide.loaders.FolderList.refresh(FolderList.java:372)
        at org.openide.loaders.FolderList.fileDeleted(FolderList.java:493)
        at sun.reflect.GeneratedMethodAccessor9.invoke(GeneratedMethodAccessor9.java:0)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:451)
        at $Proxy1.fileDeleted(.java:0)
        at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEventImpl(FCLSupport.java:145)
        at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEvent(FCLSupport.java:125)
        at org.openide.filesystems.FCLSupport$1.run(FCLSupport.java:173)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:602)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1084)