diff --git a/MidiPlayer.Droid/Properties/AndroidManifest.xml b/MidiPlayer.Droid/Properties/AndroidManifest.xml
index f33a178..9911f6d 100644
--- a/MidiPlayer.Droid/Properties/AndroidManifest.xml
+++ b/MidiPlayer.Droid/Properties/AndroidManifest.xml
@@ -1,7 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.studio.meowtoon.midiplayer" android:installLocation="auto">
 	<uses-sdk android:minSdkVersion="29" android:targetSdkVersion="29" />
-	<application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/Base.Theme.MaterialComponents.Light.DarkActionBar.Bridge"></application>
+	<application android:allowBackup="true" 
+				 android:icon="@mipmap/ic_launcher" 
+				 android:label="@string/app_name" 
+				 android:roundIcon="@mipmap/ic_launcher_round" 
+				 android:supportsRtl="true" 
+				 android:theme="@style/Base.Theme.MaterialComponents.Light.DarkActionBar.Bridge" 
+				 android:requestLegacyExternalStorage="true" 
+				 >
+	</application>
 	<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 	<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 	<uses-feature android:name="android.software.midi" android:required="true" />
diff --git a/MidiPlayer.FluidSynth/MidiPlayer.FluidSynth.csproj b/MidiPlayer.FluidSynth/MidiPlayer.FluidSynth.csproj
index 7b76755..4eaac08 100644
--- a/MidiPlayer.FluidSynth/MidiPlayer.FluidSynth.csproj
+++ b/MidiPlayer.FluidSynth/MidiPlayer.FluidSynth.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netstandard2.1</TargetFramework>
-    <DefineConstants>RUNTIME_WINDOWS</DefineConstants>
+    <DefineConstants>RUNTIME_LINUX</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/MidiPlayer.Midi/StandardMidiFile.cs b/MidiPlayer.Midi/StandardMidiFile.cs
index 627b4c4..ed25715 100644
--- a/MidiPlayer.Midi/StandardMidiFile.cs
+++ b/MidiPlayer.Midi/StandardMidiFile.cs
@@ -1,4 +1,5 @@
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -22,21 +23,25 @@ public class StandardMidiFile {
         // Constructor
 
         public StandardMidiFile(string target) {
-            _sequence = new Sequence();
-            _sequence.Format = 1;
-            _sequence.Load(target);
-            Map<int, (string name, int channel)> nameAndMidiChannelMap;
-            nameAndMidiChannelMap = new Map<int, (string name, int channel)>();
-            Enumerable.Range(0, _sequence.Count).ToList().ForEach(x => {
-                nameAndMidiChannelMap.Add(x, getTrackNameAndMidiChannel(x));
-            });
-            this._nameAndMidiChannelMap = new Map<int, (string name, int channel)>();
-            var idx = 0;
-            nameAndMidiChannelMap.ToList().ForEach(x => {
-                if (!x.Value.name.Equals("System Setup") && !(x.Value.name.Equals("") && x.Value.channel == -1)) { // no need track
-                    this._nameAndMidiChannelMap.Add(idx++, x.Value);
-                }
-            });
+            try {
+                _sequence = new Sequence();
+                _sequence.Format = 1;
+                _sequence.Load(target);
+                Map<int, (string name, int channel)> nameAndMidiChannelMap;
+                nameAndMidiChannelMap = new Map<int, (string name, int channel)>();
+                Enumerable.Range(0, _sequence.Count).ToList().ForEach(x => {
+                    nameAndMidiChannelMap.Add(x, getTrackNameAndMidiChannel(x));
+                });
+                this._nameAndMidiChannelMap = new Map<int, (string name, int channel)>();
+                var idx = 0;
+                nameAndMidiChannelMap.ToList().ForEach(x => {
+                    if (!x.Value.name.Equals("System Setup") && !(x.Value.name.Equals("") && x.Value.channel == -1)) { // no need track
+                        this._nameAndMidiChannelMap.Add(idx++, x.Value);
+                    }
+                });
+            } catch (Exception ex) {
+                Log.Error(ex.Message);
+            }
         }
 
         ///////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/MidiPlayer/Env.cs b/MidiPlayer/Env.cs
index 7c432fb..98f3e96 100644
--- a/MidiPlayer/Env.cs
+++ b/MidiPlayer/Env.cs
@@ -8,74 +8,49 @@ namespace MidiPlayer {
     public class Env {
 #nullable enable
 
-        ///////////////////////////////////////////////////////////////////////////////////////////////
-        // static Fields [nouns, noun phrases]
-
-        static string _soundFontDir = "Music";
-
-        static string _midiFileDir = "Music";
-
         ///////////////////////////////////////////////////////////////////////////////////////////////
         // static Properties [noun, noun phrase, adjective] 
 
         public static string SoundFontDir {
-            get {
-                if (!Conf.Value.Synth.SoundFontDir.Equals("undefined")) {
-                    _soundFontDir = Conf.Value.Synth.SoundFontDir;
-                }
-                return _soundFontDir;
-            }
-            set {
-                Conf.Value.Synth.SoundFontDir = value;
-            }
+            get => Conf.Value.Synth.SoundFontDir;
+            set => Conf.Value.Synth.SoundFontDir = value;
         }
 
         public static string MidiFileDir {
-            get {
-                if (!Conf.Value.Synth.MidiFileDir.Equals("undefined")) {
-                    _midiFileDir = Conf.Value.Synth.MidiFileDir;
-                }
-                return _midiFileDir;
-            }
-            set {
-                Conf.Value.Synth.MidiFileDir = value;
-            }
+            get => Conf.Value.Synth.MidiFileDir;
+            set => Conf.Value.Synth.MidiFileDir = value;
         }
 
         public static string SoundFontDirForIntent {
             get {
-                return _soundFontDir.Replace("/storage/emulated/0/", "").Replace("/", "%2F");
+                if (!ExistsSoundFont) {
+                    return "Music";
+                }
+                return SoundFontDir.Replace("/storage/emulated/0/", "").Replace("/", "%2F");
             }
         }
 
         public static string MidiFileDirForIntent {
             get {
-                return _midiFileDir.Replace("/storage/emulated/0/", "").Replace("/", "%2F");
+                if (!ExistsMidiFile) {
+                    return "Music";
+                }
+                return MidiFileDir.Replace("/storage/emulated/0/", "").Replace("/", "%2F");
             }
         }
 
         public static string SoundFontName {
-            get {
-                return Conf.Value.Synth.SoundFontName;
-            }
-            set {
-                Conf.Value.Synth.SoundFontName = value;
-            }
+            get => Conf.Value.Synth.SoundFontName;
+            set => Conf.Value.Synth.SoundFontName = value;
         }
 
         public static string MidiFileName {
-            get {
-                return Conf.Value.Synth.MidiFileName;
-            }
-            set {
-                Conf.Value.Synth.MidiFileName = value;
-            }
+            get => Conf.Value.Synth.MidiFileName;
+            set => Conf.Value.Synth.MidiFileName = value;
         }
 
         public static string SoundFontPath {
-            get {
-                return $"{SoundFontDir}/{SoundFontName}";
-            }
+            get => $"{SoundFontDir}/{SoundFontName}";
             set {
                 SoundFontDir = value.ToDirectoryName();
                 SoundFontName = value.ToFileName();
@@ -83,9 +58,7 @@ public static string SoundFontPath {
         }
 
         public static string MidiFilePath {
-            get {
-                return $"{MidiFileDir}/{MidiFileName}";
-            }
+            get => $"{MidiFileDir}/{MidiFileName}";
             set {
                 MidiFileDir = value.ToDirectoryName();
                 MidiFileName = value.ToFileName();
@@ -93,15 +66,11 @@ public static string MidiFilePath {
         }
 
         public static bool ExistsSoundFont {
-            get {
-                return File.Exists(SoundFontPath);
-            }
+            get => File.Exists(SoundFontPath);
         }
 
         public static bool ExistsMidiFile {
-            get {
-                return File.Exists(MidiFilePath);
-            }
+            get => File.Exists(MidiFilePath);
         }
     }
 }