To reproduce this probably requires precise timing;  I was running NetBeans with
a 900Mb heap (working on compiling the entire JDK with Ant - it's big).  After a
compiler error I opened a shell and renamed Version-template.java (see below) to
Version.java to make it compilable.

I attempted to close the editor window open on Version-template.java - but
enough stuff was swapped that this happened very slowly.  In the shell, I then
renamed the file, and then clicked in the (still open) tab for
Version-template.java, which no longer exists.

The following exception was thrown.  I'm not saying that this type of thing is a
common case, but code that does this sort of IO should handle a
FileNotFoundException gracefully, rather than show the user a stack trace.

Annotation: C:\Documents and Settings\Tim
Boudreau\Desktop\foo\j2se\src\share\classes\sun\misc\Version-template.java (The
system cannot find the file specified)
Annotation: C:\Documents and Settings\Tim
Boudreau\Desktop\foo\j2se\src\share\classes\sun\misc\Version-template.java (The
system cannot find the file specified)
Annotation: C:\Documents and Settings\Tim
Boudreau\Desktop\foo\j2se\src\share\classes\sun\misc\Version-template.java (The
system cannot find the file specified)
java.io.FileNotFoundException: C:\Documents and Settings\Tim
Boudreau\Desktop\foo\j2se\src\share\classes\sun\misc\Version-template.java (The
system cannot find the file specified)
	at
org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObj.getInputStream(FileObj.java:114)
	at
org.netbeans.modules.masterfs.MasterFileObject.getInputStream(MasterFileObject.java:148)
	at
org.netbeans.modules.javacore.parser.ASTProvider.getRealSource(ASTProvider.java:200)
	at org.netbeans.modules.javacore.parser.ASTProvider.getReader(ASTProvider.java:230)
	at
org.netbeans.modules.javacore.parser.ASTProvider.getSourceText(ASTProvider.java:473)
	at
org.netbeans.modules.javacore.jmiimpl.javamodel.ResourceImpl.createMDRParser(ResourceImpl.java:569)
	at
org.netbeans.modules.javacore.jmiimpl.javamodel.ResourceImpl.directUpdate(ResourceImpl.java:694)
	at
org.netbeans.modules.javacore.jmiimpl.javamodel.ResourceImpl.checkUpToDate(ResourceImpl.java:650)
	at
org.netbeans.modules.javacore.jmiimpl.javamodel.ResourceImpl.checkUpToDate(ResourceImpl.java:593)
	at
org.netbeans.modules.javacore.jmiimpl.javamodel.ResourceImpl.getClassifiers(ResourceImpl.java:171)
	at org.netbeans.jmi.javamodel.Resource$Impl.getClassifiers(Unknown Source)
	at
org.netbeans.modules.java.navigation.jmi.JUtils.getClassMembers(JUtils.java:1370)
	at
org.netbeans.modules.java.navigation.ClassMemberModel.loadContents(ClassMemberModel.java:310)
	at
org.netbeans.modules.java.navigation.spi.ListModelSupport$Loader.run(ListModelSupport.java:966)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:541)
[catch] at
org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:963)
Caused by: java.io.FileNotFoundException: C:\Documents and Settings\Tim
Boudreau\Desktop\foo\j2se\src\share\classes\sun\misc\Version-template.java (The
system cannot find the file specified)
	at java.io.FileInputStream.open(Native Method)
	at java.io.FileInputStream.<init>(FileInputStream.java:106)
	at
org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObj$2.<init>(FileObj.java:101)
	at
org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObj.getInputStream(FileObj.java:101)
	... 15 more
Caused by: org.openide.util.Exceptions$AnnException: msg
	at org.openide.util.Exceptions$AnnException.findOrCreate(Exceptions.java:191)
	at org.openide.util.Exceptions$AnnException.findOrCreate(Exceptions.java:205)
	at org.openide.util.Exceptions.attachLocalizedMessage(Exceptions.java:70)
	at
org.netbeans.modules.masterfs.filebasedfs.utils.FSException.annotateException(FSException.java:127)
	at
org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObj.getInputStream(FileObj.java:126)
	... 15 more