diff -r 41daedd8e427 openide.filesystems/src/org/openide/filesystems/FileUtil.java
--- a/openide.filesystems/src/org/openide/filesystems/FileUtil.java	Mon Sep 07 12:55:52 2015 +0200
+++ b/openide.filesystems/src/org/openide/filesystems/FileUtil.java	Mon Sep 07 14:39:32 2015 +0200
@@ -821,6 +821,11 @@
         File retVal = (File) fo.getAttribute("java.io.File"); // NOI18N;        
 
         if (retVal == null) {
+            try {
+                if (fo.getFileSystem() instanceof JarFileSystem) return null;
+            } catch (FileStateInvalidException ex) {
+                return null;
+            }
             URL fileURL = URLMapper.findURL(fo, URLMapper.INTERNAL);
             if (fileURL == null || !"file".equals(fileURL.getProtocol())) {  //NOI18N
                 fileURL = URLMapper.findURL(fo, URLMapper.EXTERNAL);