diff --git a/Vocaluxe/Base/CMain.cs b/Vocaluxe/Base/CMain.cs
index 3a131649..b8ec6bfe 100644
--- a/Vocaluxe/Base/CMain.cs
+++ b/Vocaluxe/Base/CMain.cs
@@ -822,7 +822,14 @@ namespace Vocaluxe.Base
 
         public void Close(ref CVideoStream stream)
         {
-            CVideo.Close(ref stream);
+            try
+            {
+                CVideo.Close(ref stream);
+            }
+            catch (NotSupportedException e)
+            {
+                CLog.LogError($"Clould not close the background video: {e.Message}");
+            }
         }
 
         public void SetLoop(CVideoStream stream, bool loop = true)
@@ -832,12 +839,26 @@ namespace Vocaluxe.Base
 
         public void Pause(CVideoStream stream)
         {
-            CVideo.Pause(stream);
+            try
+            {
+                CVideo.Pause(stream);
+            }
+            catch (NotSupportedException e)
+            {
+                CLog.LogError($"Clould not pause the background video: {e.Message}");
+            }
         }
 
         public void Resume(CVideoStream stream)
         {
-            CVideo.Resume(stream);
+            try
+            {
+                CVideo.Resume(stream);
+            }
+            catch (NotSupportedException e)
+            {
+                CLog.LogError($"Clould not resume the background video: {e.Message}");
+            }
         }
     }
 
diff --git a/Vocaluxe/Base/CVideo.cs b/Vocaluxe/Base/CVideo.cs
index d9400cc8..d9af124b 100644
--- a/Vocaluxe/Base/CVideo.cs
+++ b/Vocaluxe/Base/CVideo.cs
@@ -15,6 +15,7 @@
 // along with Vocaluxe. If not, see <http://www.gnu.org/licenses/>.
 #endregion
 
+using System;
 using Vocaluxe.Lib.Video;
 using VocaluxeLib;
 
@@ -61,6 +62,10 @@ namespace Vocaluxe.Base
 
         public static CVideoStream Load(string videoFileName)
         {
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
             return _VideoDecoder.Load(videoFileName);
         }
 
@@ -73,41 +78,109 @@ namespace Vocaluxe.Base
 
         public static float GetLength(CVideoStream stream)
         {
+            if (stream == null)
+            {
+                throw new ArgumentException("stream is null");
+            }
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             return _VideoDecoder.GetLength(stream);
         }
 
         public static bool GetFrame(CVideoStream stream, float time)
         {
+            if (stream == null)
+            {
+                throw new ArgumentException("stream is null");
+            }
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             return _VideoDecoder.GetFrame(stream, time);
         }
 
         public static bool Skip(CVideoStream stream, float start, float gap)
         {
+            if (stream == null)
+            {
+                throw new ArgumentException("stream is null");
+            }
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             return _VideoDecoder.Skip(stream, start, gap);
         }
 
         public static void SetLoop(CVideoStream stream, bool loop)
         {
+            if (stream == null)
+            {
+                throw new ArgumentException("stream is null");
+            }
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             _VideoDecoder.SetLoop(stream, loop);
         }
 
         public static void Pause(CVideoStream stream)
         {
+            if (stream == null)
+            {
+                throw new ArgumentException("stream is null");
+            }
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             _VideoDecoder.Pause(stream);
         }
 
         public static void Resume(CVideoStream stream)
         {
+            if (stream == null)
+            {
+                throw new ArgumentException("stream is null");
+            }
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             _VideoDecoder.Resume(stream);
         }
 
         public static bool Finished(CVideoStream stream)
         {
+            if (stream == null)
+            {
+                throw new ArgumentException("stream is null");
+            }
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             return _VideoDecoder.Finished(stream);
         }
 
         public static void Update()
         {
+            if (_VideoDecoder == null)
+            {
+                throw new NotSupportedException("_VideoDecoder is null (already closed?)");
+            }
+
             _VideoDecoder.Update();
         }
         #endregion Interface
diff --git a/Vocaluxe/Lib/Sound/Record/PortAudio/CPortAudioRecord.cs b/Vocaluxe/Lib/Sound/Record/PortAudio/CPortAudioRecord.cs
index 4702e400..cfc8818c 100644
--- a/Vocaluxe/Lib/Sound/Record/PortAudio/CPortAudioRecord.cs
+++ b/Vocaluxe/Lib/Sound/Record/PortAudio/CPortAudioRecord.cs
@@ -16,6 +16,8 @@
 #endregion
 
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using System.Runtime.InteropServices;
 using System.Threading;
 using Vocaluxe.Base;
@@ -142,9 +144,13 @@ namespace Vocaluxe.Lib.Sound.Record.PortAudio
 
             foreach (IntPtr handle in _RecHandle)
             {
-                PortAudioSharp.PortAudio.Pa_StopStream(handle);
-                PortAudioSharp.PortAudio.Pa_CloseStream(handle);
+                if (handle != IntPtr.Zero)
+                {
+                    PortAudioSharp.PortAudio.Pa_StopStream(handle);
+                    PortAudioSharp.PortAudio.Pa_CloseStream(handle);
+                }
             }
+            _RecHandle = new IntPtr[_Devices.Count];
             return true;
         }
 
@@ -153,13 +159,17 @@ namespace Vocaluxe.Lib.Sound.Record.PortAudio
         /// </summary>
         public override void Close()
         {
-            if (_RecHandle != null)
+            if (_RecHandle != null && _RecHandle.Length > 0)
             {
                 foreach (IntPtr handle in _RecHandle)
                 {
                     if (handle != IntPtr.Zero)
+                    {
                         _PaHandle.CloseStream(handle);
+                    }
                 }
+
+                _RecHandle = new IntPtr[_Devices.Count];
             }
             if (_PaHandle != null)
             {