Troubleshooting

gCMOB Not Connecting?: How to Fix Device Offline, Login Failed and Live View Errors

When gCMOB stops connecting, the fault is almost always in one of three places: your phone’s internet, the DVR or NVR’s internet, or the login saved in the app.

This guide shows you how to find which one in two minutes, then fix it step by step for every common gCMOB error.

Quick answer

Only your phone fails?

Update gCMOB, switch between Wi-Fi and mobile data, and turn off any VPN or data saver.

Offline on every phone?

The recorder has lost internet. Check its network cable, router and P2P status.

Find Where the Problem Is

Match what you see to the table below. It tells you which part to fix, so you don’t waste time resetting things that work.

What you see	Where the problem is	Go to
Device shows Offline on every phone	The recorder or its router	Check P2P status
Works on home Wi-Fi, fails on mobile data	How the device was added (local IP)	Wi-Fi only fix
Works on one phone, not on another	That phone or its saved login	Quick checks
Login failed or user locked	The username or password saved in gCMOB	Login fixes
Live view keeps loading or stays black	Internet speed or stream quality	Live view fixes
No picture even on the recorder’s monitor	Camera, cable or power, not gCMOB	Check the camera wiring

Look at the recorder's own monitor first. If the cameras show live video there, the cameras and the recorder are fine and the fault is in the network or the app.

Quick Checks: Fix Most Problems in 5 Minutes

Work through these in order. Most connection errors clear up before you reach the end of the list.

Update gCMOB

Install the latest version from Google Play (3.4.1, released June 2026). Older builds can stop connecting after server changes.

Restart everything

Close gCMOB fully and restart your phone. Then switch off the router and the DVR/NVR, wait two minutes and switch them back on.

Switch networks

Try Wi-Fi, then mobile data. If one works and the other doesn't, the problem is that network, not the recorder.

Turn off VPN and data saver

VPNs, ad blockers and Android's Data Saver can block video traffic. Allow gCMOB unrestricted mobile and background data.

Check the recorder's cable

The LAN port light on the DVR/NVR should blink. Reseat the network cable at both the recorder and the router.

Check the router's internet

Open a website on another device on the same router. If it has no internet, the recorder is offline too; contact your internet provider.

Fix gCMOB Errors by Message

Find the message gCMOB shows you, then follow the fixes from top to bottom.

Device shows Offline

Likely cause: The recorder has no internet, P2P is turned off, or the router blocks it.

Check the P2P status on the DVR (steps below)
Set the recorder’s DNS to 8.8.8.8 and 8.8.4.4
Restart the router, then the recorder

Login failed / wrong password

Likely cause: The password was changed on the DVR but not in gCMOB, or it was typed wrong.

Open Device Manager, edit the device and re-enter the username and password
Remember passwords are case-sensitive
Delete the device and add it again if editing doesn’t help

User locked

Likely cause: Too many wrong password attempts, often from another phone or PC that still has an old password.

Stop all logins and wait, or restart the recorder (lock time varies by model)
Update the password on every phone and PC that uses this recorder
Forgot it? Reset it from the recorder’s own monitor; gCMOB can’t reset it

Network timeout / connection failed

Likely cause: Slow or unstable internet at either end, or a wrong IP address or port.

Switch the camera to Sub/Extra stream
For IP/Domain devices, check the public IP or DDNS name and the TCP port (often 37777)
Test on a different network

Works on Wi-Fi, not on mobile data

Likely cause: The device was added by its local IP (such as 192.168.1.108), which only works at home.

Add the device again by serial number (P2P / InstaOn)
Or set up port forwarding and DDNS for IP/Domain access
Allow mobile data for gCMOB in Android settings

Live view loading or black screen

Likely cause: The main stream is too heavy for the upload speed, or the camera has lost its feed.

Switch to the Sub/Extra (SD) stream
Open 4 channels instead of 16
Check that the channel shows video on the recorder’s monitor

Playback: no recordings found

Likely cause: Hard disk error, no recording schedule, or the recorder’s date and time are wrong.

Check the HDD status in gCMOB or the DVR menu
Make sure the recording schedule is on
Correct the recorder’s date, time and time zone

QR code won't scan

Likely cause: Low light, glare or a damaged sticker.

Clean the label and add more light
Type the serial number by hand
Scan the QR code shown in the recorder’s P2P menu instead

No motion alerts

Likely cause: Notifications are off, or battery saving stops gCMOB in the background.

Allow notifications for gCMOB in Android settings
Turn off battery optimisation for gCMOB
Make sure motion detection is enabled on the recorder

1How to Check P2P (InstaOn) Status on Your DVR or NVR

P2P lets gCMOB reach your recorder by its serial number without port forwarding. If P2P shows Offline on the recorder, gCMOB will show the device as Offline too.

1Open the network menu

On the recorder’s monitor, right-click and open Main Menu.
Go to Network (on some models Settings → Network).
Menu names vary by model and firmware, but the options are the same.

2Check TCP/IP and DNS

Make sure the IP address, subnet mask and gateway match your router (for example gateway 192.168.1.1).
Set Preferred DNS to 8.8.8.8 and Alternate DNS to 8.8.4.4.
If DHCP gives no address, set a static IP in your router’s range and click Apply.

3Turn on P2P

Open the P2P (InstaOn) tab and tick Enable, then click Apply.
Wait a few minutes. The status should change to Online.
Still Offline? Untick Enable, Apply, tick it again, Apply, then restart the recorder.

4Add it again in gCMOB

In gCMOB, open Device Manager and tap +.
Choose serial number (P2P / InstaOn) and scan or type the SN.
Enter the username and password and tap Start Live Preview.

CP Plus notes that a recorder can take 5 to 10 minutes to show online after it connects, so give it time before trying the next fix.

If the recorder has no internet, gCMOB can still save the device, but it stays Offline until the recorder is back online.

P2P vs IP/Domain: What to Check

gCMOB connects in one of two ways. Check the one you used when you added the device.

Check	P2P / InstaOn (serial number)	IP/Domain
How it connects	Through CP Plus servers using the serial number	Directly to your public IP or DDNS name
Port forwarding	Not needed	Needed: forward the TCP port (often 37777)
Works behind CGNAT	Yes	No; ask your provider for a public IP
Common failure	P2P shows Offline on the recorder	Public IP changed or port closed
Best for	Most homes and shops	Static IP or advanced setups

Many broadband and fibre plans share one public IP between several customers (CGNAT). Port forwarding can't work on those connections, so use P2P by serial number instead.

Still Not Working? Contact CP Plus Support

If none of the fixes work, the recorder may need a firmware update or a repair. Send CP Plus these details so they can help faster.

What to send

Recorder model and firmware version (Main Menu → System Info)
Serial number from the sticker
Your gCMOB version and phone model
A screenshot of the error and of the P2P status screen
The fixes you have already tried

How to contact

Email CP Plus at support@cpplusworld.com, the support address on the gCMOB Google Play listing.

You can also open More → Help Center inside gCMOB.

Want to watch your cameras on a computer?

See how to use gCMOB on Windows with CP Plus KVMS Pro or BlueStacks.