diff --git a/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtil.java b/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtil.java
index 0d18a7b12c3b..c3404b86cf8a 100644
--- a/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtil.java
+++ b/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtil.java
@@ -82,10 +82,18 @@ public static boolean isSingleSourceFile(FileObject fObj) {
     }
 
     public static boolean isSupportedFile(FileObject file) {
+        if (file == null) {
+            return false;
+        }
         try {
-            return !MultiSourceRootProvider.DISABLE_MULTI_SOURCE_ROOT &&
-                   FileOwnerQuery.getOwner(file) == null &&
-                   !file.getFileSystem().isReadOnly();
+            FileObject dir = file.getParent();
+            File dirFile = dir != null ? FileUtil.toFile(dir) : null;
+            return !MultiSourceRootProvider.DISABLE_MULTI_SOURCE_ROOT
+                    && FileOwnerQuery.getOwner(file) == null
+                    && !file.getFileSystem().isReadOnly()
+                    && !(dirFile != null
+                    && dirFile.getName().startsWith("vcs-")
+                    && dirFile.getAbsolutePath().startsWith(System.getProperty("java.io.tmpdir")));
         } catch (FileStateInvalidException ex) {
             return false;
         }
diff --git a/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/queries/MultiSourceRootProvider.java b/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/queries/MultiSourceRootProvider.java
index ad76218b3e4a..22f80a9770e9 100644
--- a/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/queries/MultiSourceRootProvider.java
+++ b/java/java.file.launcher/src/org/netbeans/modules/java/file/launcher/queries/MultiSourceRootProvider.java
@@ -21,8 +21,6 @@
 import java.beans.PropertyChangeListener;
 import java.beans.PropertyChangeSupport;
 import java.io.IOException;
-import java.lang.ref.Reference;
-import java.lang.ref.WeakReference;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -35,6 +33,8 @@
 import java.util.Set;
 import java.util.WeakHashMap;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import javax.swing.event.ChangeEvent;
 import javax.swing.event.ChangeListener;
 import org.netbeans.api.java.classpath.ClassPath;
@@ -50,7 +50,9 @@
 import org.netbeans.modules.java.file.launcher.spi.SingleFileOptionsQueryImplementation;
 import org.netbeans.spi.java.classpath.ClassPathFactory;
 import org.netbeans.spi.java.classpath.ClassPathImplementation;
+
 import static org.netbeans.spi.java.classpath.ClassPathImplementation.PROP_RESOURCES;
+
 import org.netbeans.spi.java.classpath.ClassPathProvider;
 import org.netbeans.spi.java.classpath.FilteringPathResourceImplementation;
 import org.netbeans.spi.java.classpath.PathResourceImplementation;
@@ -58,7 +60,6 @@
 import org.openide.filesystems.FileObject;
 import org.openide.filesystems.FileUtil;
 import org.openide.filesystems.URLMapper;
-import org.openide.util.Exceptions;
 import org.openide.util.NbBundle.Messages;
 import org.openide.util.lookup.ServiceProvider;
 import org.openide.util.lookup.ServiceProviders;
@@ -69,6 +70,8 @@
 })
 public class MultiSourceRootProvider implements ClassPathProvider {
 
+    private static final Logger LOG = Logger.getLogger(MultiSourceRootProvider.class.getName());
+
     public static boolean DISABLE_MULTI_SOURCE_ROOT = false;
 
     //TODO: the cache will probably be never cleared, as the ClassPath/value refers to the key(?)
@@ -130,7 +133,7 @@ private ClassPath getSourcePath(FileObject file) {
                             return srcCP;
                         });
                     } catch (IOException ex) {
-                        Exceptions.printStackTrace(ex);
+                        LOG.log(Level.FINE, "Failed to read sourcefile " + file, ex);
                     }
                     return null;
                 });
diff --git a/java/java.file.launcher/test/unit/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtilTest.java b/java/java.file.launcher/test/unit/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtilTest.java
index c9e63c0d6fac..5ad96c09c670 100644
--- a/java/java.file.launcher/test/unit/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtilTest.java
+++ b/java/java.file.launcher/test/unit/src/org/netbeans/modules/java/file/launcher/SingleSourceFileUtilTest.java
@@ -18,9 +18,13 @@
  */
 package org.netbeans.modules.java.file.launcher;
 
+import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
 import org.junit.Test;
+
 import static org.junit.Assert.*;
+
 import org.openide.filesystems.FileObject;
 import org.openide.filesystems.FileUtil;
 import org.openide.util.Lookup;
@@ -51,4 +55,31 @@ public void testCanFindSiblingClass() throws IOException {
 
         assertTrue("Sibling found", SingleSourceFileUtil.hasClassSibling(java));
     }
+
+    @Test
+    public void testIsSupportedFile() throws IOException {
+        File vcsDemoDir = null;
+        File supportedFile = null;
+        File unsupportedFile = null;
+        try {
+            vcsDemoDir = Files.createTempDirectory("vcs-dummy").toFile();
+            supportedFile = Files.createTempFile("dummy", ".java").toFile();
+            unsupportedFile = new File(vcsDemoDir, "dummy.java");
+            FileUtil.createData(unsupportedFile);
+
+            assertTrue(SingleSourceFileUtil.isSupportedFile(FileUtil.createData(supportedFile)));
+            assertFalse(SingleSourceFileUtil.isSupportedFile(FileUtil.createData(unsupportedFile)));
+
+        } finally {
+            if(supportedFile != null && supportedFile.exists()) {
+                supportedFile.delete();
+            }
+            if(unsupportedFile != null && unsupportedFile.exists()) {
+                unsupportedFile.delete();
+            }
+            if(vcsDemoDir != null && vcsDemoDir.exists()) {
+                vcsDemoDir.delete();
+            }
+        }
+    }
 }