diff --git a/Tools/lib-novalogic/PFF/PffArchive.cs b/Tools/lib-novalogic/PFF/PffArchive.cs
index 49604ba..d6f9f3e 100644
--- a/Tools/lib-novalogic/PFF/PffArchive.cs
+++ b/Tools/lib-novalogic/PFF/PffArchive.cs
@@ -11,7 +11,7 @@ namespace Novalogic.PFF
     public class PffArchive : IDisposable
     {
         private readonly BinaryReader _bReader;
-        private readonly Header_Pff3_20 _header;
+        private readonly IPffHeaderAbstract _header;
         private List<PffEntry> _cachedEntries;
 
         private PffArchive(FileInfo fileInfo)
@@ -29,7 +29,8 @@ private PffArchive(FileInfo fileInfo)
 
             else if (version == PffVersion.PFF2 && headerSize == 20)
                 _header = reader.ReadBytes(20).ToStruct<Header_Pff3_20>();
-
+            else if (version == PffVersion.PFF4 && headerSize == 20)
+                _header = reader.ReadBytes(20).ToStruct<Header_Pff4_20>();
             else
                 throw new NotImplementedException();
         }
@@ -105,6 +106,16 @@ private IEnumerable<PffEntry> EnumerateDirectory()
                     else
                         throw new NotImplementedException();
                 }
+                else if (_header.Signature == PffVersion.PFF4)
+                {
+                    if (_header.RecordSize == 36)
+                    {
+                        var entry = _bReader.ReadBytes(36).ToStruct<Entry_Pff4_36>();
+                        pffEntry = new PffEntry(_bReader, entry, _header.Signature);
+                    }
+                    else
+                        throw new NotImplementedException();
+                }
                 else
                     throw new NotImplementedException();
 
@@ -127,10 +138,19 @@ internal interface IPffEntryAbstract
             Byte[] FileName { get; }
         }
 
+        internal interface IPffHeaderAbstract
+        {
+            UInt32 HeaderSize { get; }
+            PffVersion Signature { get; }
+            UInt32 RecordCount { get; }
+            UInt32 RecordSize { get; }
+            UInt32 RecordOffset { get; }
+        }
+
         // ReSharper disable UnassignedGetOnlyAutoProperty
 
         [StructLayout(LayoutKind.Sequential, Size = 20, Pack = 1)]
-        private struct Header_Pff3_20
+        private struct Header_Pff3_20 : IPffHeaderAbstract
         {
             public UInt32 HeaderSize { get; }
             public PffVersion Signature { get; }
@@ -151,10 +171,33 @@ private struct Entry_Pff3_32 : IPffEntryAbstract
             public Byte Null { get; }
         }
 
+        [StructLayout(LayoutKind.Sequential, Size = 20, Pack = 1)]
+        private struct Header_Pff4_20 : IPffHeaderAbstract
+        {
+            public UInt32 HeaderSize { get; }
+            public PffVersion Signature { get; }
+            public UInt32 RecordCount { get; }
+            public UInt32 RecordSize { get; }
+            public UInt32 RecordOffset { get; }
+        }
+
+        [StructLayout(LayoutKind.Sequential, Size = 32, Pack = 1)]
+        private struct Entry_Pff4_36 : IPffEntryAbstract
+        {
+            public UInt32 Deleted { get; }
+            public UInt32 FileOffset { get; }
+            public UInt32 FileSize { get; }
+            public UInt32 FileModified { get; }
+            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 15)] private readonly Byte[] fileName;
+            public Byte[] FileName => fileName;
+            public Byte Null { get; }
+        }
+
         internal enum PffVersion : uint
         {
             PFF2 = 0x32464650, //{'P','F','F','2'}
             PFF3 = 0x33464650, //{'P','F','F','3'}
+            PFF4 = 0x34464650, //{'P','F','F','4'}
         }
         
         // ReSharper restore UnassignedGetOnlyAutoProperty
diff --git a/Tools/lib-novalogic/PFF/PffEntry.cs b/Tools/lib-novalogic/PFF/PffEntry.cs
index 03161d6..1898961 100644
--- a/Tools/lib-novalogic/PFF/PffEntry.cs
+++ b/Tools/lib-novalogic/PFF/PffEntry.cs
@@ -37,7 +37,7 @@ internal PffEntry(BinaryReader reader, PffArchive.IPffEntryAbstract entry, PffAr
         public byte[] GetContents()
         {
             if ((_version == PffArchive.PffVersion.PFF3 && _entry.Deleted == 0 && _entry.FileOffset != uint.MaxValue) ||
-                _version == PffArchive.PffVersion.PFF2)
+                _version == PffArchive.PffVersion.PFF2 || _version == PffArchive.PffVersion.PFF4)
             {
 
                 var stream = _reader.BaseStream;
diff --git a/Tools/vsk/FormPreview.cs b/Tools/vsk/FormPreview.cs
index 6f3d515..bce9d46 100644
--- a/Tools/vsk/FormPreview.cs
+++ b/Tools/vsk/FormPreview.cs
@@ -59,38 +59,41 @@ private void LoadFile(PffEntry entry)
 
             Bitmap img;
             var ext = Path.GetExtension(entry.FilePath)?.Substring(1);
-            switch (ext)
+            switch (ext.ToLower())
             {
-                case "PCX":
+                case "pcx":
                     img = PcxConvert.LoadPcx(fileContents);
                     ClientSize = img.Size;
                     pictureBox.Image = img;
                     pictureBox.Visible = true;
                     break;
-                case "TGA":
+                case "tga":
                     img = TgaConvert.LoadTga(fileContents);
                     ClientSize = img.Size;
                     pictureBox.Image = img;
                     pictureBox.Visible = true;
                     break;
-                case "JPG":
+                case "jpg":
                     img = LoadBitmap(fileContents);
                     ClientSize = img.Size;
                     pictureBox.Image = img;
                     pictureBox.Visible = true;
                     break;
-                case "WAV":
+                case "wav":
                     using (var stream = new MemoryStream(fileContents))
                     {
                         var simpleSound = new SoundPlayer(stream);
                         simpleSound.Play();
                     }
                     break;
-                case "3DI":
+                case "3di":
                     var file = File3di.Open(fileContents);
                     _renderer = new ModelRenderer(renderControl, file);
                     renderControl.Visible = true;
                     break;
+                default:
+                    MessageBox.Show("Can't preview this file");
+                    break;
             }
         }