diff --git a/dev/App/User.js b/dev/App/User.js
index ed016196d..566c5b637 100644
--- a/dev/App/User.js
+++ b/dev/App/User.js
@@ -694,7 +694,7 @@ class AppUser extends AbstractApp {
 						folder.messageCountUnread(folder.messageCountUnread() - alreadyUnread);
 					}
 
-					Remote.messageSetSeen(()=>{}, sFolderFullNameRaw, rootUids, true);
+					Remote.messageSetSeen(()=>0, sFolderFullNameRaw, rootUids, true);
 					break;
 
 				case MessageSetAction.UnsetSeen:
@@ -707,7 +707,7 @@ class AppUser extends AbstractApp {
 						folder.messageCountUnread(folder.messageCountUnread() - alreadyUnread + rootUids.length);
 					}
 
-					Remote.messageSetSeen(()=>{}, sFolderFullNameRaw, rootUids, false);
+					Remote.messageSetSeen(()=>0, sFolderFullNameRaw, rootUids, false);
 					break;
 
 				case MessageSetAction.SetFlag:
@@ -715,7 +715,7 @@ class AppUser extends AbstractApp {
 						MessageFlagsCache.storeBySetAction(sFolderFullNameRaw, sSubUid, iSetAction)
 					);
 
-					Remote.messageSetFlagged(()=>{}, sFolderFullNameRaw, rootUids, true);
+					Remote.messageSetFlagged(()=>0, sFolderFullNameRaw, rootUids, true);
 					break;
 
 				case MessageSetAction.UnsetFlag:
@@ -723,7 +723,7 @@ class AppUser extends AbstractApp {
 						MessageFlagsCache.storeBySetAction(sFolderFullNameRaw, sSubUid, iSetAction)
 					);
 
-					Remote.messageSetFlagged(()=>{}, sFolderFullNameRaw, rootUids, false);
+					Remote.messageSetFlagged(()=>0, sFolderFullNameRaw, rootUids, false);
 					break;
 				// no default
 			}
@@ -968,7 +968,7 @@ class AppUser extends AbstractApp {
 						}, 1000);
 
 						setTimeout(this.quota, 5000);
-						setTimeout(() => Remote.appDelayStart(()=>{}), 35000);
+						setTimeout(() => Remote.appDelayStart(()=>0), 35000);
 
 						// When auto-login is active
 						if (
diff --git a/dev/Common/Selector.js b/dev/Common/Selector.js
index 4f5e5002d..f60d438ec 100644
--- a/dev/Common/Selector.js
+++ b/dev/Common/Selector.js
@@ -218,9 +218,9 @@ export class Selector {
 
 	itemSelected(item) {
 		if (this.isListChecked()) {
-			item || (this.oCallbacks.ItemSelect || (()=>{}))(null);
+			item || (this.oCallbacks.ItemSelect || (()=>0))(null);
 		} else if (item) {
-			(this.oCallbacks.ItemSelect || (()=>{}))(item);
+			(this.oCallbacks.ItemSelect || (()=>0))(item);
 		}
 	}
 
@@ -258,7 +258,7 @@ export class Selector {
 					const item = getItem(this.sItemSelector);
 					if (item) {
 						this.focusedItem(item);
-						(this.oCallbacks.MiddleClick || (()=>{}))(item);
+						(this.oCallbacks.MiddleClick || (()=>0))(item);
 					}
 				}
 			});
diff --git a/dev/Common/Utils.js b/dev/Common/Utils.js
index 6c7aa0e31..5518073af 100644
--- a/dev/Common/Utils.js
+++ b/dev/Common/Utils.js
@@ -83,7 +83,7 @@ let __themeTimer = 0,
  * @param {function=} themeTrigger = noop
  * @returns {void}
  */
-export function changeTheme(value, themeTrigger = ()=>{}) {
+export function changeTheme(value, themeTrigger = ()=>0) {
 	const themeStyle = elementById('app-theme-style'),
 		clearTimer = () => {
 			__themeTimer = setTimeout(() => themeTrigger(SaveSettingsStep.Idle), 1000);
diff --git a/dev/Knoin/AbstractScreen.js b/dev/Knoin/AbstractScreen.js
index a5210bbf0..50de820fa 100644
--- a/dev/Knoin/AbstractScreen.js
+++ b/dev/Knoin/AbstractScreen.js
@@ -44,7 +44,7 @@ export class AbstractScreen {
 			const routes = this.routes();
 			if (arrayLength(routes)) {
 				let route = new Crossroads(),
-					fMatcher = (this.onRoute || (()=>{})).bind(this);
+					fMatcher = (this.onRoute || (()=>0)).bind(this);
 
 				routes.forEach(item => item && route && (route.addRoute(item[0], fMatcher).rules = item[1]));
 
diff --git a/dev/Knoin/Knoin.js b/dev/Knoin/Knoin.js
index 4124fba59..a58566a57 100644
--- a/dev/Knoin/Knoin.js
+++ b/dev/Knoin/Knoin.js
@@ -27,15 +27,13 @@ export const ViewType = {
  * @returns {Function}
  */
 export function createCommand(fExecute, fCanExecute = true) {
-	let fResult = null;
-
-	fResult = fExecute
+	let fResult = fExecute
 		? (...args) => {
 			if (fResult && fResult.canExecute && fResult.canExecute()) {
 				fExecute.apply(null, args);
 			}
 			return false;
-		} : ()=>{};
+		} : ()=>0;
 	fResult.enabled = ko.observable(true);
 	fResult.isCommand = true;
 
diff --git a/dev/Model/FolderCollection.js b/dev/Model/FolderCollection.js
index 7acabd935..12eeb7f79 100644
--- a/dev/Model/FolderCollection.js
+++ b/dev/Model/FolderCollection.js
@@ -141,7 +141,7 @@ export class FolderCollectionModel extends AbstractCollectionModel
 		FolderUserStore.archiveFolder(normalizeFolder(SettingsGet('ArchiveFolder')));
 
 		if (update) {
-			rl.app.Remote.saveSystemFolders(()=>{}, {
+			rl.app.Remote.saveSystemFolders(()=>0, {
 				SentFolder: FolderUserStore.sentFolder(),
 				DraftFolder: FolderUserStore.draftFolder(),
 				SpamFolder: FolderUserStore.spamFolder(),
diff --git a/dev/Settings/User/Folders.js b/dev/Settings/User/Folders.js
index 7f30d88cb..b17d32323 100644
--- a/dev/Settings/User/Folders.js
+++ b/dev/Settings/User/Folders.js
@@ -120,23 +120,23 @@ export class FoldersUserSettings {
 
 	subscribeFolder(folder) {
 		Local.set(ClientSideKeyName.FoldersLashHash, '');
-		Remote.folderSetSubscribe(()=>{}, folder.fullNameRaw, true);
+		Remote.folderSetSubscribe(()=>0, folder.fullNameRaw, true);
 		folder.subscribed(true);
 	}
 
 	unSubscribeFolder(folder) {
 		Local.set(ClientSideKeyName.FoldersLashHash, '');
-		Remote.folderSetSubscribe(()=>{}, folder.fullNameRaw, false);
+		Remote.folderSetSubscribe(()=>0, folder.fullNameRaw, false);
 		folder.subscribed(false);
 	}
 
 	checkableTrueFolder(folder) {
-		Remote.folderSetCheckable(()=>{}, folder.fullNameRaw, true);
+		Remote.folderSetCheckable(()=>0, folder.fullNameRaw, true);
 		folder.checkable(true);
 	}
 
 	checkableFalseFolder(folder) {
-		Remote.folderSetCheckable(()=>{}, folder.fullNameRaw, false);
+		Remote.folderSetCheckable(()=>0, folder.fullNameRaw, false);
 		folder.checkable(false);
 	}
 }
diff --git a/dev/View/Popup/FolderSystem.js b/dev/View/Popup/FolderSystem.js
index 75f5612fa..145402d10 100644
--- a/dev/View/Popup/FolderSystem.js
+++ b/dev/View/Popup/FolderSystem.js
@@ -59,7 +59,7 @@ class FolderSystemPopupView extends AbstractViewPopup {
 			},
 			fSaveSystemFolders = (()=>{
 				fSetSystemFolders();
-				Remote.saveSystemFolders(()=>{}, {
+				Remote.saveSystemFolders(()=>0, {
 					SentFolder: FolderUserStore.sentFolder(),
 					DraftFolder: FolderUserStore.draftFolder(),
 					SpamFolder: FolderUserStore.spamFolder(),
diff --git a/dev/View/User/MailBox/MessageList.js b/dev/View/User/MailBox/MessageList.js
index c92adaecb..796a80ed7 100644
--- a/dev/View/User/MailBox/MessageList.js
+++ b/dev/View/User/MailBox/MessageList.js
@@ -500,7 +500,7 @@ export class MessageListMailBoxUserView extends AbstractViewRight {
 							MessageFlagsCache.clearFolder(sFolderFullNameRaw);
 						}
 
-						Remote.messageSetSeenToAll(()=>{}, sFolderFullNameRaw, true, sThreadUid ? uids : null);
+						Remote.messageSetSeenToAll(()=>0, sFolderFullNameRaw, true, sThreadUid ? uids : null);
 						break;
 					case MessageSetAction.UnsetSeen:
 						folder = getFolderFromCacheList(sFolderFullNameRaw);
@@ -526,7 +526,7 @@ export class MessageListMailBoxUserView extends AbstractViewRight {
 							MessageFlagsCache.clearFolder(sFolderFullNameRaw);
 						}
 
-						Remote.messageSetSeenToAll(()=>{}, sFolderFullNameRaw, false, sThreadUid ? uids : null);
+						Remote.messageSetSeenToAll(()=>0, sFolderFullNameRaw, false, sThreadUid ? uids : null);
 						break;
 					// no default
 				}
diff --git a/dev/View/User/MailBox/MessageView.js b/dev/View/User/MailBox/MessageView.js
index 3d97f04e1..f50ee5577 100644
--- a/dev/View/User/MailBox/MessageView.js
+++ b/dev/View/User/MailBox/MessageView.js
@@ -646,7 +646,7 @@ class MessageViewMailBoxUserView extends AbstractViewRight {
 		let oMessage = MessageUserStore.message()
 		if (oMessage && oMessage.readReceipt()) {
 			Remote.sendReadReceiptMessage(
-				()=>{},
+				()=>0,
 				oMessage.folder,
 				oMessage.uid,
 				oMessage.readReceipt(),