diff --git a/app/build.gradle b/app/build.gradle
index 14c9b64b..24e2d0f9 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -20,7 +20,7 @@ android {
         minSdkVersion 16
         targetSdkVersion 29
         versionCode 57
-        versionName "4.19"
+        versionName "4.19-hotfix1"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         multiDexEnabled true
         vectorDrawables.useSupportLibrary = true
@@ -64,7 +64,7 @@ dependencies {
     implementation "androidx.biometric:biometric:1.0.1"
     implementation 'androidx.multidex:multidex:2.0.1'
     implementation "com.daimajia.swipelayout:library:1.2.0@aar"
-    implementation 'com.google.android.material:material:1.3.0-alpha01'
+    implementation 'com.google.android.material:material:1.3.0-alpha02'
     implementation 'com.google.firebase:firebase-core:17.4.4'
     implementation 'com.google.firebase:firebase-analytics:17.4.4'
     implementation 'com.google.firebase:firebase-crashlytics:17.1.1'
diff --git a/app/release/output.json b/app/release/output-metadata.json
similarity index 89%
rename from app/release/output.json
rename to app/release/output-metadata.json
index 5ed5f0b4..7f90aa3e 100644
--- a/app/release/output.json
+++ b/app/release/output-metadata.json
@@ -12,7 +12,7 @@
       "filters": [],
       "properties": [],
       "versionCode": 57,
-      "versionName": "57",
+      "versionName": "4.19-hotfix1",
       "enabled": true,
       "outputFile": "app-release.apk"
     }
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 d91cc987..6bb1f7ac 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
@@ -130,7 +130,7 @@ class DownloadWorker private constructor(context: Context) : ContextWrapper(cont
     *  Float.POSITIVE_INFINITY -> Download completed
     */
     val progress = SparseArray<MutableList<Float>?>()
-    val notification = SparseArray<NotificationCompat.Builder>()
+    val notification = SparseArray<NotificationCompat.Builder?>()
 
     private val loop = loop()
     private val worker = SparseArray<Job?>()
@@ -255,7 +255,7 @@ class DownloadWorker private constructor(context: Context) : ContextWrapper(cont
         if (notification[galleryID] == null)
             initNotification(galleryID)
 
-        notification[galleryID].setContentTitle(reader.galleryInfo.title)
+        notification[galleryID]?.setContentTitle(reader.galleryInfo.title)
         notify(galleryID)
 
         if (isCompleted(galleryID)) {
@@ -345,7 +345,7 @@ class DownloadWorker private constructor(context: Context) : ContextWrapper(cont
                 ?.setContentText("$progress/$max")
 
         if (Cache(this).isDownloading(galleryID) && notification[galleryID] != null)
-            notificationManager.notify(galleryID, notification[galleryID].build())
+            notification[galleryID]?.let { notificationManager.notify(galleryID, it.build()) }
         else
             notificationManager.cancel(galleryID)
     }
@@ -383,7 +383,7 @@ class DownloadWorker private constructor(context: Context) : ContextWrapper(cont
                 initNotification(galleryID)
 
             if (Cache(this@DownloadWorker).isDownloading(galleryID))
-                notificationManager.notify(galleryID, notification[galleryID].build())
+                notification[galleryID]?.let { notificationManager.notify(galleryID, it.build()) }
 
             worker.put(galleryID, download(galleryID))
             queue.poll()
diff --git a/app/src/main/res/layout-v21/activity_main_content.xml b/app/src/main/res/layout-v23/activity_main_content.xml
similarity index 100%
rename from app/src/main/res/layout-v21/activity_main_content.xml
rename to app/src/main/res/layout-v23/activity_main_content.xml
diff --git a/build.gradle b/build.gradle
index 5eb988a2..0ff7d69d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,7 +7,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.0.0'
+        classpath 'com.android.tools.build:gradle:4.0.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
         classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
         classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"