diff --git a/app/src/main/java/io/nekohasekai/sagernet/ktx/Dialogs.kt b/app/src/main/java/io/nekohasekai/sagernet/ktx/Dialogs.kt
index e95a346e0..7204b30e2 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/ktx/Dialogs.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/ktx/Dialogs.kt
@@ -19,6 +19,7 @@
 
 package io.nekohasekai.sagernet.ktx
 
+import android.app.Activity
 import android.content.Context
 import androidx.appcompat.app.AlertDialog
 import androidx.fragment.app.Fragment
@@ -32,4 +33,15 @@ fun Context.alert(text: String): AlertDialog {
         .create()
 }
 
-fun Fragment.alert(text: String) = requireContext().alert(text)
\ No newline at end of file
+fun Fragment.alert(text: String) = requireContext().alert(text)
+
+fun AlertDialog.tryToShow() {
+    try {
+        val activity = context as Activity
+        if (!activity.isFinishing) {
+            show()
+        }
+    } catch (e: Exception) {
+        Logs.e(e)
+    }
+}
diff --git a/app/src/main/java/io/nekohasekai/sagernet/ui/AssetsActivity.kt b/app/src/main/java/io/nekohasekai/sagernet/ui/AssetsActivity.kt
index e9e005dfd..d354f16bb 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/ui/AssetsActivity.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/ui/AssetsActivity.kt
@@ -260,7 +260,7 @@ class AssetsActivity : ThemedActivity() {
                         updateAsset(file, versionFile, localVersion)
                     }.onFailure {
                         onMainDispatcher {
-                            alert(it.readableMessage).show()
+                            alert(it.readableMessage).tryToShow()
                         }
                     }
 
diff --git a/app/src/main/java/io/nekohasekai/sagernet/ui/BackupFragment.kt b/app/src/main/java/io/nekohasekai/sagernet/ui/BackupFragment.kt
index 15cc86f94..3cfa5b9a2 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/ui/BackupFragment.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/ui/BackupFragment.kt
@@ -254,7 +254,7 @@ class BackupFragment : NamedFragment(R.layout.layout_backup) {
                         }.onFailure {
                             Logs.w(it)
                             onMainDispatcher {
-                                alert(it.readableMessage).show()
+                                alert(it.readableMessage).tryToShow()
                             }
                         }
 
diff --git a/app/src/main/java/io/nekohasekai/sagernet/ui/ConfigurationFragment.kt b/app/src/main/java/io/nekohasekai/sagernet/ui/ConfigurationFragment.kt
index de59ad8e5..cebba46aa 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/ui/ConfigurationFragment.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/ui/ConfigurationFragment.kt
@@ -115,7 +115,12 @@ class ConfigurationFragment @JvmOverloads constructor(
     val securityAdvisory by lazy { DataStore.securityAdvisory }
 
     fun getCurrentGroupFragment(): GroupFragment? {
-        return childFragmentManager.findFragmentByTag("f" + DataStore.selectedGroup) as GroupFragment?
+        return try {
+            childFragmentManager.findFragmentByTag("f" + DataStore.selectedGroup) as GroupFragment?
+        } catch (e: Exception) {
+            Logs.e(e)
+            null
+        }
     }
 
     val updateSelectedCallback = object : ViewPager2.OnPageChangeCallback() {
@@ -1737,7 +1742,7 @@ class ConfigurationFragment @JvmOverloads constructor(
                     val msg = Protocols.genFriendlyMsg(err)
                     profileStatus.text = if (msg != err) msg else getString(R.string.unavailable)
                     profileStatus.setOnClickListener {
-                        alert(err).show()
+                        alert(err).tryToShow()
                     }
                 } else {
                     profileStatus.setOnClickListener(null)
diff --git a/app/src/main/java/io/nekohasekai/sagernet/ui/GroupFragment.kt b/app/src/main/java/io/nekohasekai/sagernet/ui/GroupFragment.kt
index ccd80efd4..2738ed43c 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/ui/GroupFragment.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/ui/GroupFragment.kt
@@ -461,17 +461,17 @@ class GroupFragment : ToolbarFragment(R.layout.layout_group),
             if (subscription != null && subscription.bytesUsed > 0L) { // SIP008 & Open Online Config
                 groupTraffic.isVisible = true
                 groupTraffic.text = if (subscription.bytesRemaining > 0L) {
-                    getString(
+                    app.getString(
                         R.string.subscription_traffic, Formatter.formatFileSize(
-                            context, subscription.bytesUsed
+                            app, subscription.bytesUsed
                         ), Formatter.formatFileSize(
-                            context, subscription.bytesRemaining
+                            app, subscription.bytesRemaining
                         )
                     )
                 } else {
-                    getString(
+                    app.getString(
                         R.string.subscription_used, Formatter.formatFileSize(
-                            context, subscription.bytesUsed
+                            app, subscription.bytesUsed
                         )
                     )
                 }