diff --git a/src/Beutl.Extensions.FFmpeg/FFmpegPath.cs b/src/Beutl.Extensions.FFmpeg/FFmpegPath.cs
index 5dc92fe24..4c4eee7b1 100644
--- a/src/Beutl.Extensions.FFmpeg/FFmpegPath.cs
+++ b/src/Beutl.Extensions.FFmpeg/FFmpegPath.cs
@@ -1,7 +1,11 @@
-using System.Reflection;
+using System.Diagnostics;
+using System.Reflection;
+
+using Beutl.Services;
 
 using FFmpeg.AutoGen;
 
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 
 #if FFMPEG_BUILD_IN
@@ -23,17 +27,41 @@ static FFmpegLoader()
 
     public static void Initialize()
     {
-        if (!_isInitialized)
-            throw new InvalidOperationException("Not initialized.");
-
-        s_logger.LogInformation("avcodec_license() {License}", ffmpeg.avcodec_license());
-        s_logger.LogInformation("avdevice_license() {License}", ffmpeg.avdevice_license());
-        s_logger.LogInformation("avfilter_license() {License}", ffmpeg.avfilter_license());
-        s_logger.LogInformation("avformat_license() {License}", ffmpeg.avformat_license());
-        s_logger.LogInformation("avutil_license() {License}", ffmpeg.avutil_license());
-        s_logger.LogInformation("postproc_license() {License}", ffmpeg.postproc_license());
-        s_logger.LogInformation("swresample_license() {License}", ffmpeg.swresample_license());
-        s_logger.LogInformation("swscale_license() {License}", ffmpeg.swscale_license());
+        try
+        {
+            if (!_isInitialized)
+                throw new InvalidOperationException("Not initialized.");
+
+            s_logger.LogInformation("avcodec_license() {License}", ffmpeg.avcodec_license());
+            s_logger.LogInformation("avdevice_license() {License}", ffmpeg.avdevice_license());
+            s_logger.LogInformation("avfilter_license() {License}", ffmpeg.avfilter_license());
+            s_logger.LogInformation("avformat_license() {License}", ffmpeg.avformat_license());
+            s_logger.LogInformation("avutil_license() {License}", ffmpeg.avutil_license());
+            s_logger.LogInformation("postproc_license() {License}", ffmpeg.postproc_license());
+            s_logger.LogInformation("swresample_license() {License}", ffmpeg.swresample_license());
+            s_logger.LogInformation("swscale_license() {License}", ffmpeg.swscale_license());
+        }
+        catch
+        {
+            INotificationService ns = ServiceLocator.Current.GetRequiredService<INotificationService>();
+            ns.Show(new Notification(
+                "FFmpeg error",
+                "FFmpegがインストールされているかを確認してください。",
+                NotificationType.Error,
+                OnActionButtonClick: OpenDocumentUrl,
+                ActionButtonText: "ドキュメントを開く"));
+
+            throw;
+        }
+    }
+
+    private static void OpenDocumentUrl()
+    {
+        Process.Start(new ProcessStartInfo("https://github.com/b-editor/beutl-docs/blob/main/ja/ffmpeg-install.md")
+        {
+            UseShellExecute = true,
+            Verb = "open"
+        });
     }
 
     public static string GetExecutable()