diff --git a/changelog/unreleased/default-extension b/changelog/unreleased/default-extension
new file mode 100644
index 00000000000..de2f1243797
--- /dev/null
+++ b/changelog/unreleased/default-extension
@@ -0,0 +1,6 @@
+Change: Configurable default extension
+
+We introduced a config option in the config.json file which allows to configure the default extension for ownCloud Web.
+Any of the configured extension ids can be chosen as default extension. If none is provided, we fall back to the files extension.
+
+https://github.com/owncloud/phoenix/pull/4382
diff --git a/changelog/unreleased/extension-loading b/changelog/unreleased/extension-loading
new file mode 100644
index 00000000000..2a0c67d6a58
--- /dev/null
+++ b/changelog/unreleased/extension-loading
@@ -0,0 +1,6 @@
+Bugfix: Unavailable extensions causing route duplication
+
+There was an error in the extension loading handlers which caused routes to be loaded multiple times when extensions from the config.json were unavailable.
+We hardened the extension loading handlers to just skip those extensions.
+
+https://github.com/owncloud/phoenix/pull/4382
diff --git a/src/components/Avatar.vue b/src/components/Avatar.vue
index 4346995f6c6..7a561050fb6 100644
--- a/src/components/Avatar.vue
+++ b/src/components/Avatar.vue
@@ -62,9 +62,9 @@ export default {
     }
   },
   computed: {
-    ...mapGetters(['getToken']),
+    ...mapGetters(['getToken', 'configuration']),
     enabled: function() {
-      return this.$root.config.enableAvatars || true
+      return this.configuration.enableAvatars || true
     }
   },
   watch: {
@@ -92,7 +92,7 @@ export default {
         return
       }
       const headers = new Headers()
-      const instance = this.$root.config.server || window.location.origin
+      const instance = this.configuration.server || window.location.origin
       const url = instance + '/remote.php/dav/avatars/' + this.userid + '/128.png'
       headers.append('Authorization', 'Bearer ' + this.getToken)
       headers.append('X-Requested-With', 'XMLHttpRequest')
diff --git a/src/components/Top-Bar.vue b/src/components/Top-Bar.vue
index b3af3ea9fc7..6174de4686e 100644
--- a/src/components/Top-Bar.vue
+++ b/src/components/Top-Bar.vue
@@ -32,7 +32,6 @@
 
 <script>
 import { mapGetters } from 'vuex'
-import pluginHelper from '../mixins/pluginHelper.js'
 import ApplicationsMenu from './ApplicationsMenu.vue'
 import UserMenu from './UserMenu.vue'
 import Notifications from './Notifications.vue'
@@ -45,7 +44,6 @@ export default {
     UserMenu,
     SearchBar
   },
-  mixins: [pluginHelper],
   props: {
     userId: {
       type: String,
diff --git a/src/mixins/pluginHelper.js b/src/mixins/pluginHelper.js
deleted file mode 100644
index b45d17f0455..00000000000
--- a/src/mixins/pluginHelper.js
+++ /dev/null
@@ -1,26 +0,0 @@
-export default {
-  methods: {
-    /**
-     * Path to application file
-     *
-     * @param exp Extensionpoint
-     * @param plugin Plugin
-     */
-
-    getPlugin(ext) {
-      return this.$root.plugins.find(n => {
-        if (n.extend === ext) {
-          return n
-        }
-      })
-    },
-
-    getPlugins(ext) {
-      return this.$root.plugins.filter(n => {
-        if (n.extend === ext) {
-          return n
-        }
-      })
-    }
-  }
-}
diff --git a/src/phoenix.js b/src/phoenix.js
index 3b5592c6ed8..89b973322c1 100644
--- a/src/phoenix.js
+++ b/src/phoenix.js
@@ -1,5 +1,5 @@
 /* eslint-disable */
-import "regenerator-runtime/runtime"
+import 'regenerator-runtime/runtime'
 
 // --- Libraries and Plugins ---
 import Vue from 'vue'
@@ -7,12 +7,10 @@ import 'vue-resize/dist/vue-resize.css'
 import VueResize from 'vue-resize'
 
 // --- Components ---
-
 import Phoenix from './Phoenix.vue'
 import missingConfigPage from './pages/missingConfig.vue'
 
 // --- Adding global libraries ---
-
 import OwnCloud from 'owncloud-sdk'
 
 import { sync } from 'vuex-router-sync'
@@ -20,7 +18,6 @@ import store from './store'
 import router from './router'
 
 // --- Plugins ----
-
 import VueEvents from 'vue-events'
 import VueRouter from 'vue-router'
 import VueClipboard from 'vue-clipboard2'
@@ -29,18 +26,15 @@ import VueMeta from 'vue-meta'
 import Vue2TouchEvents from 'vue2-touch-events'
 
 // --- Gettext ----
-
 import GetTextPlugin from 'vue-gettext'
 import coreTranslations from '../l10n/translations.json'
 
 // --- Image source ----
-
 import MediaSource from './plugins/mediaSource.js'
 import PhoenixPlugin from './plugins/phoenix'
 import ChunkedUpload from './plugins/upload'
 
 // --- Drag Drop ----
-
 import { Drag, Drop } from 'vue-drag-drop'
 
 // Import the Design System
@@ -48,9 +42,11 @@ import DesignSystem from 'owncloud-design-system'
 import 'owncloud-design-system/dist/system/system.css'
 
 import Avatar from './components/Avatar.vue'
-import appVersionJson from '../build/version.json'
 
 import wgxpath from 'wicked-good-xpath'
+
+import { registerClient } from './services/clientRegistration'
+
 wgxpath.install()
 
 Vue.prototype.$client = new OwnCloud()
@@ -87,94 +83,97 @@ const supportedLanguages = {
   it: 'Italiano',
   gl: 'Galego'
 }
+let translations = coreTranslations
 
-async function loadApps () {
-  let plugins = []
-  let translations = coreTranslations
+async function loadApp (path) {
+  return new Promise((resolve, reject) => {
+    requirejs([path], async function() {
+      const app = arguments[0]
 
-  let routes = [{
-    path: '/',
-    redirect: to => arguments[0].navItems[0].route
-  }]
+      if (!app.appInfo) {
+        reject('Skipping without appInfo for app ' + path)
+      }
 
-  for (let app of Array.from(arguments)) {
-    if (!app.appInfo) {
-      console.error('Try to load app with missing appInfo…')
-    }
-    if (app.routes) {
-      // rewrite relative app routes by prefix'ing their corresponding appId
-      app.routes.forEach(r => (r.path = `/${encodeURI(app.appInfo.id)}${r.path}`))
+      if (app.routes) {
+        // rewrite relative app routes by prefix'ing their corresponding appId
+        app.routes.forEach(r => (r.path = `/${encodeURI(app.appInfo.id)}${r.path}`))
+
+        // adjust routes in nav items
+        if (app.navItems) {
+          app.navItems.forEach(nav => {
+            const r = app.routes.find(function(element) {
+              return element.name === nav.route.name;
+            });
+            if (r) {
+              r.meta = r.meta || {}
+              r.meta.pageIcon = nav.iconMaterial
+              r.meta.pageTitle = nav.name
+              nav.route.path = nav.route.path || r.path
+            } else {
+              console.error(`Unknown route name ${nav.route.name}`)
+            }
+          })
+        }
+        router.addRoutes(app.routes)
+      }
 
-      // adjust routes in nav items
       if (app.navItems) {
-        app.navItems.forEach(nav => {
-          const r = app.routes.find(function(element) {
-            return element.name === nav.route.name;
-          });
-          if (r) {
-            r.meta = r.meta || {}
-            r.meta.pageIcon = nav.iconMaterial
-            r.meta.pageTitle = nav.name
-            nav.route.path = nav.route.path || r.path
-          } else {
-            console.error(`Unknown route name ${nav.route.name}`)
+        store.commit('SET_NAV_ITEMS_FROM_CONFIG', {
+          extension: app.appInfo.id,
+          navItems: app.navItems
+        })
+      }
+      if (app.translations) {
+        Object.keys(supportedLanguages).forEach((lang) => {
+          if (translations[lang] && app.translations[lang]) {
+            Object.assign(translations[lang], app.translations[lang])
           }
         })
       }
-      routes.push(app.routes)
-    }
-    if (app.plugins) {
-      plugins.push(app.plugins)
-    }
-    if (app.navItems) {
-      store.commit('SET_NAV_ITEMS_FROM_CONFIG', {
-        extension: app.appInfo.id,
-        navItems: app.navItems
-      })
-    }
-    if (app.translations) {
-      Object.keys(supportedLanguages).forEach((lang) => {
-        if (translations[lang] && app.translations[lang]) {
-          Object.assign(translations[lang], app.translations[lang])
-        }
-      })
-    }
 
-    if(app.quickActions) {
-      store.commit('ADD_QUICK_ACTIONS', app.quickActions)
-    }
+      if (app.quickActions) {
+        store.commit('ADD_QUICK_ACTIONS', app.quickActions)
+      }
 
-    if (app.store) {
-      registerStoreModule(app)
-    }
+      if (app.store) {
+        store.registerModule(app.appInfo.name, app.store.default || app.store)
+      }
+
+      await store.dispatch('registerApp', app.appInfo)
+      resolve(true)
+    }, function(err) {
+      reject("failed to load app " + path)
+    })
+  })
+}
 
-    store.dispatch('registerApp', app.appInfo)
+async function finalizeInit () {
+  // set home route
+  const appIds = store.getters.appIds
+  let defaultExtensionId = store.getters.configuration.options.defaultExtension
+  if (!defaultExtensionId || appIds.indexOf(defaultExtensionId) < 0) {
+    defaultExtensionId = appIds[0]
   }
-  router.addRoutes(routes.flat())
+  router.addRoutes([{
+    path: '/',
+    redirect: () => store.getters.getNavItemsByExtension(defaultExtensionId)[0].route
+  }])
+
+  // sync router into store
   sync(store, router)
 
   // inject custom config into vuex
-  store.dispatch('loadConfig', config)
+  await store.dispatch('loadConfig', config)
 
   // basic init of ownCloud sdk
   Vue.prototype.$client.init({ baseUrl: config.server || window.location.origin })
 
-  Vue.use(GetTextPlugin, {
-    availableLanguages: supportedLanguages,
-    defaultLanguage: navigator.language.substring(0, 2),
-    translations: translations,
-    silent: true
-  })
-
   // inject custom theme config into vuex
   await fetchTheme()
 
-  const OC = new Vue({
+  loadTranslations()
+  new Vue({
     el: '#owncloud',
-    data: {
-      config: config,
-      plugins: plugins.flat()
-    },
     store,
     router,
     render: h => h(Phoenix)
@@ -189,120 +188,42 @@ function fetchTheme() {
     fetch(`themes/${config.theme}.json`)
       .then(res => res.json())
       .then(res => {
-        store.dispatch('loadTheme', { theme: res, name: config.theme })
-        resolve(true)
+        store.dispatch('loadTheme', { theme: res, name: config.theme }).then(() => resolve(true))
       })
       .catch(err => reject(err))
   })
 }
 
-function registerStoreModule (app) {
-  if (app.store.default) {
-    return store.registerModule(app.appInfo.name, app.store.default)
-  }
-
-  return store.registerModule(app.appInfo.name, app.store)
-}
-
 function missingConfig () {
-  const translations = coreTranslations
-
-  Vue.use(GetTextPlugin, {
-    availableLanguages: supportedLanguages,
-    defaultLanguage: navigator.language.substring(0, 2),
-    translations: translations,
-    silent: true
-  })
-
-  const OC = new Vue({
+  loadTranslations()
+  new Vue({
     el: '#owncloud',
     store,
     render: h => h(missingConfigPage)
   })
 }
 
-function requireError (err) {
-  if (err) {
-    // display error to user
-    let missingApps = []
-    const failedId = err.requireModules && err.requireModules[0]
-    missingApps.push(failedId)
-    let index = apps.findIndex((a) => {
-      return failedId === a.substring(2)
-    })
-    apps.splice(index, 1)
-    config.state = 'corrupt'
-    config.corrupted = missingApps
-    requirejs(apps, loadApps, requireError)
-  } else {
-    throw err
-  }
-}
-
-async function get(url){
-  let data = await (await (fetch(url)
-    .then(res => {
-      return res.json()
-    })
-    .catch(err => {
-      console.log('Error: ', err)
-    })
-  ))
-  return data
-}
-
-async function post(url, data) {
-  let resp = await (await (fetch(url, {
-    method: 'POST',
-    headers: {
-      'Content-Type': 'application/json',
-    },
-    body: JSON.stringify(data),
+function loadTranslations () {
+  Vue.use(GetTextPlugin, {
+    availableLanguages: supportedLanguages,
+    defaultLanguage: navigator.language.substring(0, 2),
+    translations,
+    silent: true
   })
-    .then(res => {
-      return res.json()
-    })
-    .catch(err => {
-      console.log('Error: ', err)
-    })
-  ))
-  return resp
 }
 
-async function registerClient(openIdConfig) {
-  const clientData = sessionStorage.getItem('dynamicClientData')
-  if (clientData !== null) {
-    const client_secret_expires_at = clientData.client_secret_expires_at || 0;
-    if (client_secret_expires_at === 0 || Date.now() < client_secret_expires_at*1000) {
-      return JSON.parse(clientData)
-    }
-  }
-  sessionStorage.removeItem('dynamicClientData')
+(async function () {
+  config = await fetch('config.json')
 
-  let baseUrl = window.location.href.split('#')[0]
-  if (baseUrl.endsWith('/index.html')) {
-    baseUrl = baseUrl.substr(0, baseUrl.length - 10)
+  if (config.status === 404) {
+    router.push('missing-config')
+    missingConfig()
+    return
   }
 
-  const wellKnown = await get(`${openIdConfig.authority}/.well-known/openid-configuration`)
-  const resp = await post(wellKnown.registration_endpoint, {
-
-    "redirect_uris": [
-      baseUrl + 'oidc-callback.html'
-    ],
-    "client_name": `ownCloud Phoenix(${appVersionJson.version}) on ${baseUrl}`
-  })
-  sessionStorage.setItem('dynamicClientData', JSON.stringify(resp))
-  return resp
-}
-
-
-(async function () {
   try {
-    config = await fetch('config.json').catch(() => {
-      config.state = 'missing'
-    })
     config = await config.json()
+
     // if dynamic client registration is necessary - do this here now
     if (config.openIdConnect && config.openIdConnect.dynamic) {
       const clientData = await registerClient(config.openIdConnect)
@@ -310,27 +231,31 @@ async function registerClient(openIdConfig) {
       config.openIdConnect.client_secret = clientData.client_secret
     }
 
-    // Loads apps from internal server
+    // Collect internal app paths
     apps = config.apps.map((app) => {
       return `./apps/${app}/${app}.bundle.js`
     })
 
-    // Loads apps from external servers
+    // Collect external app paths
     if (config.external_apps) {
-      config.external_apps.forEach(app => apps.push(app.path))
+      apps.push(...config.external_apps.map(app => app.path))
     }
 
-    // provide global config object
-    // TODO: frozen object would be great ...
-    window.phoenixConfig = config
-
     // requirejs.config({waitSeconds:200}) is not really working ... reason unknown
     // we are manipulating requirejs directly
     requirejs.s.contexts._.config.waitSeconds = 200
 
-    requirejs(apps, loadApps, requireError)
+    // Boot apps
+    for(const path of apps) {
+      // please note that we have to go through apps one by one for now, to not break e.g. translations loading (race conditions)
+      try {
+        await loadApp(path)
+      } catch(err) {}
+    }
+
+    // Finalize loading core and apps
+    await finalizeInit()
   } catch (err) {
-    router.push('missing-config')
-    missingConfig()
+    console.log(err)
   }
 })()
diff --git a/src/services/clientRegistration.js b/src/services/clientRegistration.js
new file mode 100644
index 00000000000..e06a4a46023
--- /dev/null
+++ b/src/services/clientRegistration.js
@@ -0,0 +1,53 @@
+import appVersionJson from '../../build/version.json'
+
+async function get(url) {
+  return await fetch(url)
+    .then(res => {
+      return res.json()
+    })
+    .catch(err => {
+      console.log('Error: ', err)
+    })
+}
+
+async function post(url, data) {
+  return await fetch(url, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json'
+    },
+    body: JSON.stringify(data)
+  })
+    .then(res => {
+      return res.json()
+    })
+    .catch(err => {
+      console.log('Error: ', err)
+    })
+}
+
+export async function registerClient(openIdConfig) {
+  const clientData = sessionStorage.getItem('dynamicClientData')
+  if (clientData !== null) {
+    // eslint-disable-next-line camelcase
+    const client_secret_expires_at = clientData.client_secret_expires_at || 0
+    // eslint-disable-next-line camelcase
+    if (client_secret_expires_at === 0 || Date.now() < client_secret_expires_at * 1000) {
+      return JSON.parse(clientData)
+    }
+  }
+  sessionStorage.removeItem('dynamicClientData')
+
+  let baseUrl = window.location.href.split('#')[0]
+  if (baseUrl.endsWith('/index.html')) {
+    baseUrl = baseUrl.substr(0, baseUrl.length - 10)
+  }
+
+  const wellKnown = await get(`${openIdConfig.authority}/.well-known/openid-configuration`)
+  const resp = await post(wellKnown.registration_endpoint, {
+    redirect_uris: [baseUrl + 'oidc-callback.html'],
+    client_name: `ownCloud Phoenix(${appVersionJson.version}) on ${baseUrl}`
+  })
+  sessionStorage.setItem('dynamicClientData', JSON.stringify(resp))
+  return resp
+}
diff --git a/src/store/apps.js b/src/store/apps.js
index 758b9e5bd8c..865661bb2ee 100644
--- a/src/store/apps.js
+++ b/src/store/apps.js
@@ -111,6 +111,9 @@ const mutations = {
 }
 
 const getters = {
+  appIds: state => {
+    return Object.keys(state.meta)
+  },
   apps: state => {
     return state.meta
   },
diff --git a/src/store/config.js b/src/store/config.js
index 5ac8f48e1d9..095e1708f0b 100644
--- a/src/store/config.js
+++ b/src/store/config.js
@@ -36,6 +36,7 @@ const state = {
     }
   },
   options: {
+    defaultExtension: 'files',
     hideSearchBar: false
   }
 }