diff --git a/build.gradle b/build.gradle
index 71aed74..de96bef 100644
--- a/build.gradle
+++ b/build.gradle
@@ -14,8 +14,8 @@ buildscript {
         junitVersion = '4.13'
         androidTestVersion = '1.2.0'
         androidEspressoVersion = '3.2.0'
-        versionCode = 5000958
-        versionName = '5.1.19-nightly'
+        versionCode = 5000968
+        versionName = '5.1.20-nightly'
         resConfigs = ['ar', 'es', 'fa', 'fr', 'ja', 'ko', 'ru', 'tr', 'zh-rCN', 'zh-rTW']
     }
 
diff --git a/core/src/main/java/com/github/shadowsocks/Core.kt b/core/src/main/java/com/github/shadowsocks/Core.kt
index 38bd6d0..ae7f8f7 100644
--- a/core/src/main/java/com/github/shadowsocks/Core.kt
+++ b/core/src/main/java/com/github/shadowsocks/Core.kt
@@ -22,6 +22,8 @@ package com.github.shadowsocks
 import SpeedUpVPN.VpnEncrypt
 import android.app.*
 import android.app.admin.DevicePolicyManager
+import android.content.ClipData
+import android.content.ClipboardManager
 import android.content.Context
 import android.content.DialogInterface
 import android.content.Intent
@@ -77,6 +79,7 @@ object Core {
     val defaultDPreference by lazy { DPreference(app, app.packageName + "_preferences") }
     lateinit var configureIntent: (Context) -> PendingIntent
     val activity by lazy { app.getSystemService<ActivityManager>()!! }
+    val clipboard by lazy { app.getSystemService<ClipboardManager>()!! }
     val connectivity by lazy { app.getSystemService<ConnectivityManager>()!! }
     val notification by lazy { app.getSystemService<NotificationManager>()!! }
     val packageInfo: PackageInfo by lazy { getPackageInfo(app.packageName) }
@@ -228,6 +231,14 @@ object Core {
             if (Build.VERSION.SDK_INT >= 28) PackageManager.GET_SIGNING_CERTIFICATES
             else @Suppress("DEPRECATION") PackageManager.GET_SIGNATURES)!!
 
+    fun trySetPrimaryClip(clip: String) = try {
+        clipboard.setPrimaryClip(ClipData.newPlainText(null, clip))
+        true
+    } catch (e: RuntimeException) {
+        printLog(e)
+        false
+    }
+
     fun startService() = ContextCompat.startForegroundService(app, Intent(app, ShadowsocksConnection.serviceClass))
     fun reloadService(oldProfileId:Long, connection : ShadowsocksConnection) {
         if (ProfileManager.getProfile(oldProfileId)?.profileType == ProfileManager.getProfile(DataStore.profileId)?.profileType )
diff --git a/gitupdate.bat b/gitupdate.bat
index 2b785d4..172dc03 100644
--- a/gitupdate.bat
+++ b/gitupdate.bat
@@ -3,6 +3,6 @@ git pull origin master
 git add -A
 git commit -m "update"
 git push origin master
-git tag -a v5.1.19 -m "release v5.1.19"
+git tag -a v5.1.20 -m "release v5.1.20"
 git push origin --tags
 pause
\ No newline at end of file
diff --git a/mobile/src/main/java/com/github/shadowsocks/AppManager.kt b/mobile/src/main/java/com/github/shadowsocks/AppManager.kt
index 083b755..0d844ce 100644
--- a/mobile/src/main/java/com/github/shadowsocks/AppManager.kt
+++ b/mobile/src/main/java/com/github/shadowsocks/AppManager.kt
@@ -25,8 +25,6 @@ import android.animation.Animator
 import android.animation.AnimatorListenerAdapter
 import android.annotation.SuppressLint
 import android.content.BroadcastReceiver
-import android.content.ClipData
-import android.content.ClipboardManager
 import android.content.Intent
 import android.content.pm.ApplicationInfo
 import android.content.pm.PackageInfo
@@ -40,7 +38,6 @@ import android.widget.Filterable
 import android.widget.SearchView
 import androidx.annotation.UiThread
 import androidx.appcompat.app.AppCompatActivity
-import androidx.core.content.getSystemService
 import androidx.core.util.set
 import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.DefaultItemAnimator
@@ -50,7 +47,6 @@ import com.github.shadowsocks.Core.app
 import com.github.shadowsocks.database.ProfileManager
 import com.github.shadowsocks.preference.DataStore
 import com.github.shadowsocks.utils.DirectBoot
-import com.github.shadowsocks.utils.Key
 import com.github.shadowsocks.utils.SingleInstanceActivity
 import com.github.shadowsocks.utils.listenForPackageChanges
 import com.github.shadowsocks.widget.ListHolderListener
@@ -58,7 +54,10 @@ import com.github.shadowsocks.widget.ListListener
 import com.google.android.material.snackbar.Snackbar
 import kotlinx.android.synthetic.main.layout_apps.*
 import kotlinx.android.synthetic.main.layout_apps_item.view.*
-import kotlinx.coroutines.*
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.ensureActive
+import kotlinx.coroutines.withContext
 import me.zhanghai.android.fastscroll.FastScrollerBuilder
 import me.zhanghai.android.fastscroll.PopupTextProvider
 import kotlin.coroutines.coroutineContext
@@ -177,7 +176,6 @@ class AppManager : AppCompatActivity() {
     }
 
     private val proxiedUids = SparseBooleanArray()
-    private val clipboard by lazy { getSystemService<ClipboardManager>()!! }
     private var loader: Job? = null
     private var apps = emptyList<ProxiedApp>()
     private val appsAdapter = AppsAdapter()
@@ -267,26 +265,26 @@ class AppManager : AppCompatActivity() {
         when (item.itemId) {
             R.id.action_apply_all -> {
                 val profiles = ProfileManager.getAllProfiles()
-                if (profiles != null) {
+                if (!profiles.isNullOrEmpty()) {
                     val proxiedAppString = DataStore.individual
                     profiles.forEach {
                         it.individual = proxiedAppString
                         it.bypass = DataStore.bypass
+                        it.proxyApps = true
                         ProfileManager.updateProfile(it)
                     }
                     if (DataStore.directBootAware) DirectBoot.update()
                     Snackbar.make(list, R.string.action_apply_all, Snackbar.LENGTH_LONG).show()
-                } else Snackbar.make(list, R.string.action_export_err, Snackbar.LENGTH_LONG).show()
+                }
                 return true
             }
             R.id.action_export_clipboard -> {
-                clipboard.setPrimaryClip(ClipData.newPlainText(Key.individual,
-                        "${DataStore.bypass}\n${DataStore.individual}"))
-                Snackbar.make(list, R.string.action_export_msg, Snackbar.LENGTH_LONG).show()
+                Snackbar.make(list, if (Core.trySetPrimaryClip("${DataStore.bypass}\n${DataStore.individual}"))
+                    R.string.action_export_msg else R.string.action_export_err, Snackbar.LENGTH_LONG).show()
                 return true
             }
             R.id.action_import_clipboard -> {
-                val proxiedAppString = clipboard.primaryClip?.getItemAt(0)?.text?.toString()
+                val proxiedAppString = Core.clipboard.primaryClip?.getItemAt(0)?.text?.toString()
                 if (!proxiedAppString.isNullOrEmpty()) {
                     val i = proxiedAppString.indexOf('\n')
                     try {
diff --git a/mobile/src/main/java/com/github/shadowsocks/UdpFallbackProfileActivity.kt b/mobile/src/main/java/com/github/shadowsocks/UdpFallbackProfileActivity.kt
index b27508f..04bb908 100644
--- a/mobile/src/main/java/com/github/shadowsocks/UdpFallbackProfileActivity.kt
+++ b/mobile/src/main/java/com/github/shadowsocks/UdpFallbackProfileActivity.kt
@@ -35,14 +35,18 @@ import com.github.shadowsocks.database.Profile
 import com.github.shadowsocks.database.ProfileManager
 import com.github.shadowsocks.plugin.PluginConfiguration
 import com.github.shadowsocks.preference.DataStore
+import com.github.shadowsocks.utils.DirectBoot
 import com.github.shadowsocks.utils.SingleInstanceActivity
 import com.github.shadowsocks.utils.resolveResourceId
 import com.github.shadowsocks.widget.ListHolderListener
 import com.github.shadowsocks.widget.ListListener
+import com.google.android.material.snackbar.Snackbar
+import kotlinx.android.synthetic.main.layout_udp_fallback.*
 
 class UdpFallbackProfileActivity : AppCompatActivity() {
     inner class ProfileViewHolder(view: View) : RecyclerView.ViewHolder(view), View.OnClickListener {
         private var item: Profile? = null
+        private var pos: Int = 0
         private val text = itemView.findViewById<CheckedTextView>(android.R.id.text1)
 
         init {
@@ -50,16 +54,20 @@ class UdpFallbackProfileActivity : AppCompatActivity() {
             itemView.setOnClickListener(this)
         }
 
-        fun bind(item: Profile?) {
+        fun bind(item: Profile?, position: Int) {
             this.item = item
+            this.pos = position
             if (item == null) text.setText(R.string.plugin_disabled) else text.text = item.formattedName
             text.isChecked = udpFallback == item?.id
+            if (text.isChecked) selected = position
         }
 
         override fun onClick(v: View?) {
             DataStore.udpFallback = item?.id
             DataStore.dirty = true
-            finish()
+            udpFallback = item?.id
+            profilesAdapter.notifyItemChanged(pos)
+            profilesAdapter.notifyItemChanged(selected)
         }
     }
 
@@ -68,7 +76,8 @@ class UdpFallbackProfileActivity : AppCompatActivity() {
                 .filter { it.id != editingId && PluginConfiguration(it.plugin ?: "").selected.isEmpty() }
 
         override fun onBindViewHolder(holder: ProfileViewHolder, position: Int) =
-                holder.bind(if (position == 0) null else profiles[position - 1])
+                holder.bind(if (position == 0) null else profiles[position - 1], position)
+
         override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ProfileViewHolder = ProfileViewHolder(
                 LayoutInflater.from(parent.context).inflate(Resources.getSystem()
                         .getIdentifier("select_dialog_singlechoice_material", "layout", "android"), parent, false))
@@ -78,6 +87,7 @@ class UdpFallbackProfileActivity : AppCompatActivity() {
     private var editingId = DataStore.editingId
     private var udpFallback = DataStore.udpFallback
     private val profilesAdapter = ProfilesAdapter()
+    private var selected = 0
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -93,6 +103,22 @@ class UdpFallbackProfileActivity : AppCompatActivity() {
         toolbar.setTitle(R.string.udp_fallback)
         toolbar.setNavigationIcon(R.drawable.ic_navigation_close)
         toolbar.setNavigationOnClickListener { finish() }
+        toolbar.inflateMenu(R.menu.udp_fallback_menu)
+        toolbar.setOnMenuItemClickListener { menuItem ->
+            if (menuItem.itemId == R.id.action_apply_all) {
+                val profiles = ProfileManager.getAllProfiles()
+                if (!profiles.isNullOrEmpty()) {
+                    profiles.forEach {
+                        if (it.id == DataStore.udpFallback) return@forEach
+                        it.udpFallback = DataStore.udpFallback
+                        ProfileManager.updateProfile(it)
+                    }
+                    if (DataStore.directBootAware) DirectBoot.update()
+                    Snackbar.make(list, R.string.action_apply_all, Snackbar.LENGTH_LONG).show()
+                }
+                true
+            } else false
+        }
 
         findViewById<RecyclerView>(R.id.list).apply {
             setOnApplyWindowInsetsListener(ListListener)