Hi there! I'm sorry to hear that the DMSS app isn't working on your iPhone. Let's figure this out together. Can you tell me more about the specific issue you're experiencing? For example, are you unable to open the app at all, or is there a specific error message you're seeing? Also, have you tried any troubleshooting steps so far?

Connection failed. Check nerwork

Thanks for the additional details! The "Connection failed. Check network" message typically indicates that the DMSS app is having trouble connecting to your camera or the device you're trying to access. Let’s go through some steps to troubleshoot this.

### Step 1: Check Your Network Connection
- Ensure that your iPhone is connected to a stable Wi-Fi or cellular data network. If you're on Wi-Fi, check the signal strength; moving closer to the router can help if the signal is weak.

### Step 2: Restart the App
- Close the DMSS app completely and then reopen it. Sometimes a simple restart can resolve connectivity issues.

### Step 3: Test Your Camera Connection
- Make sure that the camera or recorder you’re trying to connect to is properly connected to your network. If possible, check the settings on the device itself to confirm it's online.

### Step 4: Reconfigure your Camera in the App
1. In the DMSS app, go to the settings where you add your devices.
2. Remove the current camera or recorder from your list.
3. Add it back by entering the correct ID or scanning the QR code, if applicable.

### Step 5: Ensure Firmware is Updated
- If you recently updated the DMSS app, check whether the firmware on your camera or NVR is up to date. Sometimes updates are essential for compatibility.

If you've tried these steps and are still encountering issues, it might be worth checking this source for other suggestions from fellow users facing similar problems or updating your NVR firmware as mentioned in a Reddit post1.

Are you satisfied with the solution I provided, or do you need further assistance?