diff --git a/web/src/components/canvas/canvas-resource-mention-textarea.tsx b/web/src/components/canvas/canvas-resource-mention-textarea.tsx
index 002f91c6c..c97b9e50e 100644
--- a/web/src/components/canvas/canvas-resource-mention-textarea.tsx
+++ b/web/src/components/canvas/canvas-resource-mention-textarea.tsx
@@ -45,7 +45,8 @@ export const CanvasResourceMentionTextarea = forwardRef<HTMLTextAreaElement, Pro
     { value, references, onChange, onSubmit, onKeyDown, className, containerClassName, style, highlightLabels = true, mentionMenuWidth = 256, sendOnEnter = true, onContentSizeChange, ...props },
     forwardedRef,
 ) {
-    const theme = canvasThemes[useThemeStore((state) => state.theme)];
+    const rawTheme = useThemeStore((state) => state.theme);
+    const theme = canvasThemes[rawTheme as keyof typeof canvasThemes] ?? canvasThemes.dark;
     const containerRef = useRef<HTMLDivElement | null>(null);
     const textareaRef = useRef<HTMLTextAreaElement | null>(null);
     const editorRef = useRef<HTMLDivElement | null>(null);
diff --git a/web/src/components/model-picker.tsx b/web/src/components/model-picker.tsx
index 4e31f2f7e..9d4b4e866 100644
--- a/web/src/components/model-picker.tsx
+++ b/web/src/components/model-picker.tsx
@@ -2,7 +2,7 @@ import { useEffect, useId, useMemo, useRef, useState, type KeyboardEvent } from
 import { Check, ChevronDown, Coins, Cpu } from "lucide-react";
 import { Popover } from "antd";
 
-import { canvasThemes } from "@/lib/canvas-theme";
+import { canvasThemes, type CanvasTheme } from "@/lib/canvas-theme";
 import { cn } from "@/lib/utils";
 import { modelDisplayName, modelOptionLabel, modelOptionName, resolveModelChannel, selectableModelsByCapability, type AiConfig, type ModelCapability } from "@/stores/use-config-store";
 import { useThemeStore } from "@/stores/use-theme-store";
@@ -24,7 +24,9 @@ type ModelPickerProps = {
 export function ModelPicker({ config, value, onChange, capability, className, fullWidth = false, placeholder = "选择模型", onMissingConfig, showSelectedPrice = true, variant = "default" }: ModelPickerProps) {
     const creditsEnabled = useUserStore((state) => state.features.creditsEnabled);
     const pickerId = useId();
-    const theme = canvasThemes[useThemeStore((state) => state.theme)];
+    // 双保险：即使 store merge 写出非法 theme，这里也兜底到 dark，避免 "reading 'node'" 崩溃
+    const rawTheme = useThemeStore((state) => state.theme);
+    const theme = (canvasThemes[rawTheme as keyof typeof canvasThemes] ?? canvasThemes.dark) as CanvasTheme;
     const [open, setOpen] = useState(false);
     const menuRef = useRef<HTMLDivElement>(null);
     const triggerRef = useRef<HTMLButtonElement>(null);
diff --git a/web/src/stores/use-config-store.ts b/web/src/stores/use-config-store.ts
index b9f5abdfb..a0843e67c 100644
--- a/web/src/stores/use-config-store.ts
+++ b/web/src/stores/use-config-store.ts
@@ -279,8 +279,9 @@ export const useConfigStore = create<ConfigStore>()(
     ),
 );
 
-export function normalizeConfigSnapshot(snapshot: ConfigStoreSnapshot) {
-    const persistedConfig = (snapshot.config || {}) as Partial<AiConfig>;
+export function normalizeConfigSnapshot(snapshot: ConfigStoreSnapshot | undefined = {}) {
+    // 坏存储/旧版本快照可能是 undefined 或缺 config，兜底为 defaultConfig，保证渲染不崩溃
+    const persistedConfig = (snapshot?.config || {}) as Partial<AiConfig>;
     const config = { ...defaultConfig, ...persistedConfig };
     const hasPersistedChannels = Array.isArray(persistedConfig.channels);
     if (!hasPersistedChannels) config.channels = [];
diff --git a/web/src/stores/use-theme-store.ts b/web/src/stores/use-theme-store.ts
index b6073cee5..466f337f8 100644
--- a/web/src/stores/use-theme-store.ts
+++ b/web/src/stores/use-theme-store.ts
@@ -8,12 +8,26 @@ type ThemeStore = {
     setTheme: (theme: ThemeName) => void;
 };
 
+const VALID_THEMES: ThemeName[] = ["light", "dark"];
+
 export const useThemeStore = create<ThemeStore>()(
     persist(
         (set) => ({
             theme: "dark",
-            setTheme: (theme) => set({ theme }),
+            // 写入前校验：非法 theme 直接忽略，防止 syncRemoteUserData 等路径绕过 merge 写入坏值
+            setTheme: (next) => set((state) => (VALID_THEMES.includes(next) ? { theme: next } : state)),
         }),
-        { name: "infinite-canvas:theme_store" },
+        {
+            name: "infinite-canvas:theme_store",
+            // 持久化恢复校验：旧版本/坏 session 写入的非法值回退到 dark，
+            // 避免 canvasThemes[非法值] = undefined 触发 "reading 'node'" 崩溃
+            merge: (persisted, current) => {
+                const stored = (persisted || {}) as Partial<ThemeStore>;
+                const theme = VALID_THEMES.includes(stored.theme as ThemeName)
+                    ? (stored.theme as ThemeName)
+                    : "dark";
+                return { ...current, theme };
+            },
+        },
     ),
 );