diff --git a/app/src/main/java/com/xypower/mpremote/DeviceActivity.java b/app/src/main/java/com/xypower/mpremote/DeviceActivity.java
index 9f27140..c52cda8 100644
--- a/app/src/main/java/com/xypower/mpremote/DeviceActivity.java
+++ b/app/src/main/java/com/xypower/mpremote/DeviceActivity.java
@@ -30,6 +30,7 @@ import com.xypower.mpremote.databinding.ActivityDeviceBinding;
 import com.xypower.mpremote.utils.AdbUtils;
 
 import org.json.JSONObject;
+import org.w3c.dom.Text;
 
 import java.io.File;
 import java.net.Socket;
@@ -106,7 +107,7 @@ public class DeviceActivity extends AppCompatActivity {
     private Map<Integer, JSONObject> mChannelCfgs = new HashMap();
     private String mSerialNo = "";
 
-    private MicroPhotoContext.AppConfig mAppConfig;
+    private MicroPhotoContext.AppConfig mAppConfig = new MicroPhotoContext.AppConfig();
     private int mBatteryVoltage = -1;
     private int mBatteryChargingVoltage = -1;
 
@@ -261,7 +262,9 @@ public class DeviceActivity extends AppCompatActivity {
                 if (res) {
 
                     final MicroPhotoContext.AppConfig appConfig = MicroPhotoContext.getMpAppConfig(context, appConfigFile.getAbsolutePath());
-                    mAppConfig = appConfig;
+                    if (appConfig != null) {
+                        mAppConfig = appConfig;
+                    }
 
                     DeviceActivity.this.mHandler.post(new Runnable() {
                         @Override
@@ -700,7 +703,7 @@ public class DeviceActivity extends AppCompatActivity {
         // SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
         // SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");
         String title = resources.getString(R.string.app_name);
-        if (!TextUtils.isEmpty(mAppConfig.cmdid)) {
+        if (mAppConfig != null && !TextUtils.isEmpty(mAppConfig.cmdid)) {
             title = mAppConfig.cmdid;
         }
         actionBar.setTitle(title);
@@ -755,7 +758,7 @@ public class DeviceActivity extends AppCompatActivity {
 
         appendKeyValue(stringBuilder, "CMDID", mAppConfig.cmdid, true);
 
-        appendKeyValue(stringBuilder, "主站", mAppConfig.server + ":" + Integer.toString(mAppConfig.port));
+        appendKeyValue(stringBuilder, "主站", (TextUtils.isEmpty(mAppConfig.server) ? "" : mAppConfig.server) + ":" + Integer.toString(mAppConfig.port));
 
         appendKeyValue(stringBuilder, "通道数", Integer.toString(mAppConfig.channels));
 
@@ -801,9 +804,9 @@ public class DeviceActivity extends AppCompatActivity {
 
     private void appendKeyValue(StringBuilder stringBuilder, String key, String val, boolean highlignt) {
         if (highlignt) {
-            stringBuilder.append(key + "：<font color=\"red\"><b>" + val + "</b></font>");
+            stringBuilder.append(key + "：<font color=\"red\"><b>" + (TextUtils.isEmpty(val) ? "" : val) + "</b></font>");
         } else {
-            stringBuilder.append(key + "：" + val);
+            stringBuilder.append(key + "：" + (TextUtils.isEmpty(val) ? "" : val));
         }
         stringBuilder.append("<br>");
     }