diff --git a/packages/frontend/src/os.ts b/packages/frontend/src/os.ts
index f656a52371..3fca924c05 100644
--- a/packages/frontend/src/os.ts
+++ b/packages/frontend/src/os.ts
@@ -294,6 +294,21 @@ export function inputText(props: {
 } | {
 	canceled: false; result: string;
 }>;
+// min lengthが指定されてたら result は null になり得ないことを保証する overload function
+export function inputText(props: {
+	type?: 'text' | 'email' | 'password' | 'url';
+	title?: string;
+	text?: string;
+	placeholder?: string | null;
+	autocomplete?: string;
+	default?: string;
+	minLength: number;
+	maxLength?: number;
+}): Promise<{
+	canceled: true; result: undefined;
+} | {
+	canceled: false; result: string;
+}>;
 export function inputText(props: {
 	type?: 'text' | 'email' | 'password' | 'url';
 	title?: string;
diff --git a/packages/frontend/src/ui/deck.vue b/packages/frontend/src/ui/deck.vue
index bdb62dca15..1356bbb073 100644
--- a/packages/frontend/src/ui/deck.vue
+++ b/packages/frontend/src/ui/deck.vue
@@ -24,7 +24,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 					:ref="id"
 					:key="id"
 					:class="$style.column"
-					:column="columns.find(c => c.id === id)"
+					:column="columns.find(c => c.id === id)!"
 					:isStacked="ids.length > 1"
 					@headerWheel="onWheel"
 				/>
@@ -185,7 +185,7 @@ const addColumn = async (ev) => {
 		'mentions',
 		'direct',
 		'roleTimeline',
-	];
+	] as const;
 
 	const { canceled, result: column } = await os.select({
 		title: i18n.ts._deck.addColumn,
@@ -194,6 +194,7 @@ const addColumn = async (ev) => {
 		})),
 	});
 	if (canceled) return;
+	if (column == null) return;
 
 	addColumnToStore({
 		type: column,
@@ -212,7 +213,7 @@ const onContextmenu = (ev) => {
 
 function onWheel(ev: WheelEvent) {
 	if (ev.deltaX === 0) {
-		columnsEl.value.scrollLeft += ev.deltaY;
+		columnsEl.value!.scrollLeft += ev.deltaY;
 	}
 }
 
diff --git a/packages/frontend/src/ui/deck/deck-store.ts b/packages/frontend/src/ui/deck/deck-store.ts
index bb3c04cd5c..e6fe6eedde 100644
--- a/packages/frontend/src/ui/deck/deck-store.ts
+++ b/packages/frontend/src/ui/deck/deck-store.ts
@@ -19,7 +19,7 @@ type ColumnWidget = {
 
 export type Column = {
 	id: string;
-	type: 'main' | 'widgets' | 'notifications' | 'tl' | 'antenna' | 'channel' | 'list' | 'mentions' | 'direct';
+	type: 'main' | 'widgets' | 'notifications' | 'tl' | 'antenna' | 'channel' | 'list' | 'mentions' | 'direct' | 'roleTimeline';
 	name: string | null;
 	width: number;
 	widgets?: ColumnWidget[];
@@ -34,7 +34,7 @@ export type Column = {
 	withRenotes?: boolean;
 	withReplies?: boolean;
 	onlyFiles?: boolean;
-	soundSetting: SoundStore;
+	soundSetting?: SoundStore;
 };
 
 export const deckStore = markRaw(new Storage('deck', {
@@ -77,7 +77,7 @@ export const loadDeck = async () => {
 			key: deckStore.state.profile,
 		});
 	} catch (err) {
-		if (err.code === 'NO_SUCH_KEY') {
+		if (typeof err === 'object' && err != null && 'code' in err && err.code === 'NO_SUCH_KEY') {
 			// 後方互換性のため
 			if (deckStore.state.profile === 'default') {
 				saveDeck();
@@ -159,6 +159,7 @@ export function swapLeftColumn(id: Column['id']) {
 			}
 			return true;
 		}
+		return false;
 	});
 	saveDeck();
 }
@@ -175,6 +176,7 @@ export function swapRightColumn(id: Column['id']) {
 			}
 			return true;
 		}
+		return false;
 	});
 	saveDeck();
 }
@@ -195,6 +197,7 @@ export function swapUpColumn(id: Column['id']) {
 			}
 			return true;
 		}
+		return false;
 	});
 	saveDeck();
 }
@@ -215,6 +218,7 @@ export function swapDownColumn(id: Column['id']) {
 			}
 			return true;
 		}
+		return false;
 	});
 	saveDeck();
 }
@@ -266,6 +270,7 @@ export function removeColumnWidget(id: Column['id'], widget: ColumnWidget) {
 	const columnIndex = deckStore.state.columns.findIndex(c => c.id === id);
 	const column = deepClone(deckStore.state.columns[columnIndex]);
 	if (column == null) return;
+	if (column.widgets == null) column.widgets = [];
 	column.widgets = column.widgets.filter(w => w.id !== widget.id);
 	columns[columnIndex] = column;
 	deckStore.set('columns', columns);
@@ -288,6 +293,7 @@ export function updateColumnWidget(id: Column['id'], widgetId: string, widgetDat
 	const columnIndex = deckStore.state.columns.findIndex(c => c.id === id);
 	const column = deepClone(deckStore.state.columns[columnIndex]);
 	if (column == null) return;
+	if (column.widgets == null) column.widgets = [];
 	column.widgets = column.widgets.map(w => w.id === widgetId ? {
 		...w,
 		data: widgetData,