diff --git a/src/components/structures/MatrixChat.js b/src/components/structures/MatrixChat.js
index fc1257922a..6d225191a8 100644
--- a/src/components/structures/MatrixChat.js
+++ b/src/components/structures/MatrixChat.js
@@ -1118,7 +1118,7 @@ module.exports = React.createClass({
         if (cli.isCryptoEnabled()) {
             const blacklistEnabled = SettingsStore.getValueAt(
                 SettingLevel.DEVICE,
-                "blacklistUnverifiedDevices"
+                "blacklistUnverifiedDevices",
             );
             cli.setGlobalBlacklistUnverifiedDevices(blacklistEnabled);
         }
diff --git a/src/components/views/elements/LanguageDropdown.js b/src/components/views/elements/LanguageDropdown.js
index 82fa9b869e..8f2ba006cf 100644
--- a/src/components/views/elements/LanguageDropdown.js
+++ b/src/components/views/elements/LanguageDropdown.js
@@ -18,7 +18,6 @@ limitations under the License.
 import React from 'react';
 
 import sdk from '../../../index';
-import UserSettingsStore from '../../../UserSettingsStore';
 import * as languageHandler from '../../../languageHandler';
 import SettingsStore from "../../../settings/SettingsStore";
 
diff --git a/src/components/views/elements/SettingsFlag.js b/src/components/views/elements/SettingsFlag.js
index cb6a001cf4..782dc30ede 100644
--- a/src/components/views/elements/SettingsFlag.js
+++ b/src/components/views/elements/SettingsFlag.js
@@ -59,7 +59,7 @@ module.exports = React.createClass({
             this.props.name,
             this.props.roomId,
             this.props.level,
-            val !== undefined ? val : this.state.value
+            val !== undefined ? val : this.state.value,
         );
     },
 
diff --git a/src/settings/Settings.js b/src/settings/Settings.js
index ef8f9ae259..3aab27bf04 100644
--- a/src/settings/Settings.js
+++ b/src/settings/Settings.js
@@ -185,7 +185,7 @@ export const SETTINGS = {
     },
     "language": {
         supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS_WITH_CONFIG,
-        default: "en"
+        default: "en",
     },
     "analyticsOptOut": {
         supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS_WITH_CONFIG,
@@ -240,4 +240,4 @@ export const SETTINGS = {
         supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
         default: false,
     },
-};
\ No newline at end of file
+};
diff --git a/src/settings/SettingsStore.js b/src/settings/SettingsStore.js
index 9b7fe42c97..db7ae807e3 100644
--- a/src/settings/SettingsStore.js
+++ b/src/settings/SettingsStore.js
@@ -14,7 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import Promise from 'bluebird';
 import DeviceSettingsHandler from "./handlers/DeviceSettingsHandler";
 import RoomDeviceSettingsHandler from "./handlers/RoomDeviceSettingsHandler";
 import DefaultSettingsHandler from "./handlers/DefaultSettingsHandler";
@@ -210,14 +209,14 @@ export default class SettingsStore {
         const handlers = SettingsStore._getHandlers(settingName);
 
         if (explicit) {
-            let handler = handlers[level];
+            const handler = handlers[level];
             if (!handler) return SettingsStore._tryControllerOverride(settingName, level, roomId, null);
             const value = handler.getValue(settingName, roomId);
             return SettingsStore._tryControllerOverride(settingName, level, roomId, value);
         }
 
         for (let i = minIndex; i < LEVEL_ORDER.length; i++) {
-            let handler = handlers[LEVEL_ORDER[i]];
+            const handler = handlers[LEVEL_ORDER[i]];
             if (!handler) continue;
             if (excludeDefault && LEVEL_ORDER[i] === "default") continue;
 
diff --git a/src/settings/controllers/SettingController.js b/src/settings/controllers/SettingController.js
index 194e7af93b..a91b616da9 100644
--- a/src/settings/controllers/SettingController.js
+++ b/src/settings/controllers/SettingController.js
@@ -46,4 +46,4 @@ export default class SettingController {
     onChange(level, roomId, newValue) {
         // do nothing by default
     }
-}
\ No newline at end of file
+}
diff --git a/src/settings/handlers/ConfigSettingsHandler.js b/src/settings/handlers/ConfigSettingsHandler.js
index e28e12c02c..7a370249a7 100644
--- a/src/settings/handlers/ConfigSettingsHandler.js
+++ b/src/settings/handlers/ConfigSettingsHandler.js
@@ -14,7 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import Promise from 'bluebird';
 import SettingsHandler from "./SettingsHandler";
 import SdkConfig from "../../SdkConfig";
 
diff --git a/src/settings/handlers/LocalEchoWrapper.js b/src/settings/handlers/LocalEchoWrapper.js
index e9a17d7698..d616edd9fb 100644
--- a/src/settings/handlers/LocalEchoWrapper.js
+++ b/src/settings/handlers/LocalEchoWrapper.js
@@ -66,4 +66,4 @@ export default class LocalEchoWrapper extends SettingsHandler {
     isSupported() {
         return this._handler.isSupported();
     }
-}
\ No newline at end of file
+}
diff --git a/src/settings/handlers/SettingsHandler.js b/src/settings/handlers/SettingsHandler.js
index 49265feb9a..69f633c650 100644
--- a/src/settings/handlers/SettingsHandler.js
+++ b/src/settings/handlers/SettingsHandler.js
@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import Promise from "bluebird";
+
 /**
  * Represents the base class for all level handlers. This class performs no logic
  * and should be overridden.
@@ -28,7 +30,8 @@ export default class SettingsHandler {
      * @returns {*} The setting value, or null if not found.
      */
     getValue(settingName, roomId) {
-        throw new Error("Operation not possible: getValue was not overridden");
+        console.error("Invalid operation: getValue was not overridden");
+        return null;
     }
 
     /**
@@ -43,7 +46,8 @@ export default class SettingsHandler {
      * @returns {Promise} Resolves when the setting has been saved.
      */
     setValue(settingName, roomId, newValue) {
-        throw new Error("Operation not possible: setValue was not overridden");
+        console.error("Invalid operation: setValue was not overridden");
+        return Promise.reject();
     }
 
     /**