diff --git a/app/src/main/java/xyz/quaver/pupil/Pupil.kt b/app/src/main/java/xyz/quaver/pupil/Pupil.kt
index 54b1b78c..1a723eec 100644
--- a/app/src/main/java/xyz/quaver/pupil/Pupil.kt
+++ b/app/src/main/java/xyz/quaver/pupil/Pupil.kt
@@ -31,10 +31,12 @@ import com.google.android.gms.common.GooglePlayServicesNotAvailableException
 import com.google.android.gms.common.GooglePlayServicesRepairableException
 import com.google.android.gms.security.ProviderInstaller
 import com.google.firebase.analytics.FirebaseAnalytics
+import com.google.firebase.crashlytics.FirebaseCrashlytics
 import xyz.quaver.proxy
 import xyz.quaver.pupil.util.Histories
 import xyz.quaver.pupil.util.getProxy
 import java.io.File
+import java.util.*
 
 class Pupil : MultiDexApplication() {
 
@@ -48,6 +50,16 @@ class Pupil : MultiDexApplication() {
     override fun onCreate() {
         val preference = PreferenceManager.getDefaultSharedPreferences(this)
 
+        val userID =
+            if (preference.getString("user_id", "").isNullOrEmpty()) {
+                UUID.randomUUID().toString().also {
+                    preference.edit().putString("user_id", it).apply()
+                }
+            } else
+                preference.getString("user_id", "") ?: ""
+
+        FirebaseCrashlytics.getInstance().setUserId(userID)
+
         proxy = getProxy(this)
 
         try {
diff --git a/app/src/main/java/xyz/quaver/pupil/ui/fragment/SettingsFragment.kt b/app/src/main/java/xyz/quaver/pupil/ui/fragment/SettingsFragment.kt
index 29eb39b3..d975355d 100644
--- a/app/src/main/java/xyz/quaver/pupil/ui/fragment/SettingsFragment.kt
+++ b/app/src/main/java/xyz/quaver/pupil/ui/fragment/SettingsFragment.kt
@@ -19,11 +19,11 @@
 package xyz.quaver.pupil.ui.fragment
 
 import android.Manifest
-import android.content.Intent
-import android.content.SharedPreferences
+import android.content.*
 import android.content.pm.PackageManager
 import android.os.Build
 import android.os.Bundle
+import android.widget.Toast
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.core.app.ActivityCompat
@@ -53,11 +53,7 @@ class SettingsFragment :
     Preference.OnPreferenceChangeListener,
     SharedPreferences.OnSharedPreferenceChangeListener {
 
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-
-        PreferenceManager.getDefaultSharedPreferences(requireContext()).registerOnSharedPreferenceChangeListener(this)
-    }
+    lateinit var sharedPreference: SharedPreferences
 
     override fun onResume() {
         super.onResume()
@@ -202,6 +198,12 @@ class SettingsFragment :
                         activity?.startActivityForResult(intent, REQUEST_IMPORT_OLD_GALLERIES_OLD)
                     }
                 }
+                "user_id" -> {
+                    (context.getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager).setPrimaryClip(
+                        ClipData.newPlainText("user_id", sharedPreference.getString("user_id", ""))
+                    )
+                    Toast.makeText(context, R.string.settings_user_id_toast, Toast.LENGTH_SHORT).show()
+                }
                 else -> return false
             }
         }
@@ -247,6 +249,9 @@ class SettingsFragment :
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         setPreferencesFromResource(R.xml.root_preferences, rootKey)
 
+        sharedPreference = PreferenceManager.getDefaultSharedPreferences(requireContext())
+        sharedPreference.registerOnSharedPreferenceChangeListener(this)
+
         initPreferences()
     }
 
@@ -293,7 +298,7 @@ class SettingsFragment :
                             onPreferenceClickListener = this@SettingsFragment
                         }
                         "default_query" -> {
-                            summary = PreferenceManager.getDefaultSharedPreferences(requireContext()).getString("default_query", "") ?: ""
+                            summary = sharedPreference.getString("default_query", "") ?: ""
 
                             onPreferenceClickListener = this@SettingsFragment
                         }
@@ -337,6 +342,10 @@ class SettingsFragment :
                         "old_import_galleries" -> {
                             onPreferenceClickListener = this@SettingsFragment
                         }
+                        "user_id" -> {
+                            summary = sharedPreference.getString("user_id", "")
+                            onPreferenceClickListener = this@SettingsFragment
+                        }
                     }
 
                 }
diff --git a/app/src/main/java/xyz/quaver/pupil/util/download/Cache.kt b/app/src/main/java/xyz/quaver/pupil/util/download/Cache.kt
index 3b78315b..deb4c25c 100644
--- a/app/src/main/java/xyz/quaver/pupil/util/download/Cache.kt
+++ b/app/src/main/java/xyz/quaver/pupil/util/download/Cache.kt
@@ -259,8 +259,12 @@ class Cache(context: Context) : ContextWrapper(context) {
                 it.createNewFile()
         }
 
-        FileOutputStream(cache).use {
-            it.write(data)
+        try {
+            FileOutputStream(cache).use {
+                it.write(data)
+            }
+        } catch (e: Exception) {
+            cache.delete()
         }
     }
 
diff --git a/app/src/main/java/xyz/quaver/pupil/util/download/DownloadWorker.kt b/app/src/main/java/xyz/quaver/pupil/util/download/DownloadWorker.kt
index 63226ab6..587a51c8 100644
--- a/app/src/main/java/xyz/quaver/pupil/util/download/DownloadWorker.kt
+++ b/app/src/main/java/xyz/quaver/pupil/util/download/DownloadWorker.kt
@@ -151,7 +151,13 @@ class DownloadWorker private constructor(context: Context) : ContextWrapper(cont
 
     val interceptor = Interceptor { chain ->
         val request = chain.request()
-        val response = chain.proceed(request)
+        var response = chain.proceed(request)
+
+        var retry = 5
+        while (!response.isSuccessful && retry > 0) {
+            response = chain.proceed(request)
+            retry--
+        }
 
         response.newBuilder()
             .body(response.body()?.let {
@@ -296,7 +302,7 @@ class DownloadWorker private constructor(context: Context) : ContextWrapper(cont
             val callback = object : Callback {
                 override fun onFailure(call: Call, e: IOException) {
                     Log.i("PUPILD", "FAIL ${call.request().tag()} (${e.message})")
-                    if (e.message != "Canceled")
+                    if (e.message?.contains("cancel", true) != true)
                         FirebaseCrashlytics.getInstance().recordException(e)
 
                     progress[galleryID]?.set(i, Float.NaN)
diff --git a/app/src/main/res/values-ja/strings.xml b/app/src/main/res/values-ja/strings.xml
index 3ad95d3d..067f2789 100644
--- a/app/src/main/res/values-ja/strings.xml
+++ b/app/src/main/res/values-ja/strings.xml
@@ -148,4 +148,6 @@
     <string name="settings_download_when_cache_disable_warning">キャッシュを使用しないため、ダウンロードできません</string>
     <string name="apcjsa_option_title">(Korean only)</string>
     <string name="apcjsa_option_message">(Korean only)</string>
+    <string name="settings_user_id">ユーザーID</string>
+    <string name="settings_user_id_toast">ユーザーIDをクリップボードにコピーしました</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values-ko/strings.xml b/app/src/main/res/values-ko/strings.xml
index d7c72021..d036521d 100644
--- a/app/src/main/res/values-ko/strings.xml
+++ b/app/src/main/res/values-ko/strings.xml
@@ -148,4 +148,6 @@
     <string name="settings_download_when_cache_disable_warning">캐시를 활성화 해야 다운로드를 진행할 수 있습니다</string>
     <string name="apcjsa_option_title">아청법 대응 옵션 추가</string>
     <string name="apcjsa_option_message">경찰서 정모 확률을 줄여보고자 캐시 비활성화/태그 필터를 추가하였습니다. 적용하시겠습니까?</string>
+    <string name="settings_user_id">유저 ID</string>
+    <string name="settings_user_id_toast">유저 ID를 클립보드에 복사했습니다</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 96ba80c2..7a2109f6 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -183,6 +183,8 @@
     <string name="settings_restore_failed">Restore failed</string>
     <string name="settings_restore_successful">%1$d entries restored</string>
     <string name="settings_import_old_galleries">Import old galleries</string>
+    <string name="settings_user_id">User ID</string>
+    <string name="settings_user_id_toast">User ID is copied to clipboard</string>
 
     <!-- SETTINGS/APP LOCK ACTIVITY -->
 
diff --git a/app/src/main/res/xml/root_preferences.xml b/app/src/main/res/xml/root_preferences.xml
index 234899ce..dff10800 100644
--- a/app/src/main/res/xml/root_preferences.xml
+++ b/app/src/main/res/xml/root_preferences.xml
@@ -107,6 +107,10 @@
             app:key="old_import_galleries"
             app:title="@string/settings_import_old_galleries"/>
 
+        <Preference
+            app:key="user_id"
+            app:title="@string/settings_user_id"/>
+
     </PreferenceCategory>
 
-</androidx.preference.PreferenceScreen>
+</androidx.preference.PreferenceScreen>
\ No newline at end of file