diff --git a/client/components/app/Appbar.vue b/client/components/app/Appbar.vue
index 2e3d8710..b04ec7f5 100644
--- a/client/components/app/Appbar.vue
+++ b/client/components/app/Appbar.vue
@@ -17,6 +17,8 @@
         <controls-global-search />
         <div class="flex-grow" />
 
+        <span v-if="showExperimentalFeatures" class="material-icons text-4xl text-warning pr-4">logo_dev</span>
+
         <nuxt-link v-if="userCanUpload" to="/upload" class="outline-none hover:text-gray-200 cursor-pointer w-8 h-8 flex items-center justify-center">
           <span class="material-icons">upload</span>
         </nuxt-link>
@@ -117,6 +119,9 @@ export default {
     },
     processingBatch() {
       return this.$store.state.processingBatch
+    },
+    showExperimentalFeatures() {
+      return this.$store.state.showExperimentalFeatures
     }
   },
   methods: {
diff --git a/client/components/app/Reader.vue b/client/components/app/Reader.vue
index fb1c2ddb..851ca79d 100644
--- a/client/components/app/Reader.vue
+++ b/client/components/app/Reader.vue
@@ -70,7 +70,7 @@ export default {
       }
     },
     fullUrl() {
-      var serverUrl = process.env.serverUrl
+      var serverUrl = process.env.serverUrl || '/local'
       return `${serverUrl}/${this.url}`
     }
   },
diff --git a/client/pages/upload/index.vue b/client/pages/upload/index.vue
index 30afb57c..62d552e7 100644
--- a/client/pages/upload/index.vue
+++ b/client/pages/upload/index.vue
@@ -120,9 +120,9 @@ export default {
       title: null,
       author: null,
       series: null,
-      acceptedAudioFormats: ['.mp3', '.m4b', '.m4a', '.flac'],
+      acceptedAudioFormats: ['.mp3', '.m4b', '.m4a', '.flac', '.opus'],
       acceptedImageFormats: ['.png', '.jpg', '.jpeg', '.webp'],
-      inputAccept: '.png, .jpg, .jpeg, .webp, .mp3, .m4b, .m4a, .flac',
+      inputAccept: '.png, .jpg, .jpeg, .webp, .mp3, .m4b, .m4a, .flac, .opus',
       isDragOver: false,
       showUploader: true,
       validAudioFiles: [],
diff --git a/client/tailwind.config.js b/client/tailwind.config.js
index 943bd4e4..15265f28 100644
--- a/client/tailwind.config.js
+++ b/client/tailwind.config.js
@@ -6,7 +6,8 @@ module.exports = {
       safelist: [
         'bg-success',
         'bg-red-600',
-        'py-1.5'
+        'py-1.5',
+        'bg-info'
       ]
     }
   },
diff --git a/server/Server.js b/server/Server.js
index e9b97421..7b52c9fa 100644
--- a/server/Server.js
+++ b/server/Server.js
@@ -439,18 +439,21 @@ class Server {
     })
   }
 
-  testFileSystem(req, res) {
+  async testFileSystem(req, res) {
     Logger.debug(`[Server] Running fs test`)
-    var paths = fs.readdir(global.appRoot)
+    var paths = await fs.readdir(global.appRoot)
     Logger.debug(paths)
     var pathMap = {}
     if (paths && paths.length) {
       for (let i = 0; i < paths.length; i++) {
         var fullPath = Path.join(global.appRoot, paths[i])
         Logger.debug('Checking path', fullPath)
-        var _paths = fs.readdir(fullPath)
-        Logger.debug(_paths)
-        pathMap[paths[i]] = _paths
+        var isDirectory = fs.lstatSync(fullPath).isDirectory()
+        if (isDirectory) {
+          var _paths = await fs.readdir(fullPath)
+          Logger.debug(_paths)
+          pathMap[paths[i]] = _paths
+        }
       }
     }
     Logger.debug('Finished fs test')
diff --git a/server/objects/Audiobook.js b/server/objects/Audiobook.js
index 90109891..ab79099e 100644
--- a/server/objects/Audiobook.js
+++ b/server/objects/Audiobook.js
@@ -390,6 +390,7 @@ class Audiobook {
         this.addTrack(file)
       }
     })
+    this.setChapters()
     this.lastUpdate = Date.now()
   }