diff --git a/desktop/package.json b/desktop/package.json
index 7eb8288..a88b255 100644
--- a/desktop/package.json
+++ b/desktop/package.json
@@ -25,7 +25,29 @@
     },
     "files": [
       "src/**/*",
-      "package.json"
+      "package.json",
+      {
+        "from": "node_modules",
+        "to": "node_modules",
+        "filter": [
+          "electron-updater/**/*",
+          "builder-util-runtime/**/*",
+          "debug/**/*",
+          "ms/**/*",
+          "sax/**/*",
+          "js-yaml/**/*",
+          "argparse/**/*",
+          "lazy-val/**/*",
+          "lodash.escaperegexp/**/*",
+          "lodash.isequal/**/*",
+          "tiny-typed-emitter/**/*",
+          "fs-extra/**/*",
+          "graceful-fs/**/*",
+          "jsonfile/**/*",
+          "universalify/**/*",
+          "semver/**/*"
+        ]
+      }
     ],
     "extraResources": [
       {
diff --git a/desktop/src/main.cjs b/desktop/src/main.cjs
index 6a0ed2c..0ed4605 100644
--- a/desktop/src/main.cjs
+++ b/desktop/src/main.cjs
@@ -8,7 +8,13 @@ const {
   dialog,
   shell,
 } = require("electron");
-const { autoUpdater } = require("electron-updater");
+let autoUpdater = null;
+let autoUpdaterLoadError = null;
+try {
+  ({ autoUpdater } = require("electron-updater"));
+} catch (err) {
+  autoUpdaterLoadError = err;
+}
 const { spawn, spawnSync } = require("child_process");
 const fs = require("fs");
 const http = require("http");
@@ -297,6 +303,12 @@ function isAutoUpdateEnabled() {
 
   const forced = parseEnvBool(process.env.AUTO_UPDATE_ENABLED);
   let enabled = forced != null ? forced : !!app.isPackaged;
+  if (enabled && !autoUpdater) {
+    enabled = false;
+    logMain(
+      `[main] auto-update disabled: electron-updater unavailable: ${autoUpdaterLoadError?.message || "unknown error"}`
+    );
+  }
 
   // In packaged builds electron-updater reads update config from app-update.yml.
   // If missing, treat auto-update as disabled to avoid noisy errors.
@@ -823,6 +835,10 @@ function getPackagedBackendPath() {
   return path.join(process.resourcesPath, "backend", "wechat-backend.exe");
 }
 
+function getPackagedWcdbDllPath() {
+  return path.join(process.resourcesPath, "backend", "native", "wcdb_api.dll");
+}
+
 function startBackend() {
   if (backendProc) return backendProc;
 
@@ -853,8 +869,17 @@ function startBackend() {
         `Packaged backend not found: ${backendExe}. Build it into desktop/resources/backend/wechat-backend.exe`
       );
     }
+    const packagedWcdbDll = getPackagedWcdbDllPath();
+    if (fs.existsSync(packagedWcdbDll)) {
+      env.WECHAT_TOOL_WCDB_API_DLL_PATH = packagedWcdbDll;
+      logMain(`[main] using packaged wcdb_api.dll: ${packagedWcdbDll}`);
+    } else {
+      logMain(`[main] packaged wcdb_api.dll not found: ${packagedWcdbDll}`);
+    }
+
+    const backendCwd = path.dirname(backendExe);
     backendProc = spawn(backendExe, [], {
-      cwd: env.WECHAT_TOOL_DATA_DIR,
+      cwd: backendCwd,
       env,
       stdio: ["ignore", "pipe", "pipe"],
       windowsHide: true,
diff --git a/src/wechat_decrypt_tool/wcdb_realtime.py b/src/wechat_decrypt_tool/wcdb_realtime.py
index a875033..4cbd53f 100644
--- a/src/wechat_decrypt_tool/wcdb_realtime.py
+++ b/src/wechat_decrypt_tool/wcdb_realtime.py
@@ -253,7 +253,9 @@ def _ensure_initialized() -> None:
             return
         rc = int(lib.wcdb_init())
         if rc != 0:
-            raise WCDBRealtimeError(f"wcdb_init failed: {rc}")
+            logs = get_native_logs(require_initialized=False)
+            hint = f" logs={logs[:6]}" if logs else ""
+            raise WCDBRealtimeError(f"wcdb_init failed: {rc}.{hint}")
         _initialized = True
 
 
@@ -315,11 +317,12 @@ def _call_out_error(fn, *args) -> None:
             pass
 
 
-def get_native_logs() -> list[str]:
-    try:
-        _ensure_initialized()
-    except Exception:
-        return []
+def get_native_logs(*, require_initialized: bool = True) -> list[str]:
+    if require_initialized:
+        try:
+            _ensure_initialized()
+        except Exception:
+            return []
     lib = _load_wcdb_lib()
     out = ctypes.c_char_p()
     rc = int(lib.wcdb_get_logs(ctypes.byref(out)))