UniFi U6+ 6.7.17 Firmware Upgrade Issue and Solution

On some UniFi U6+ access points, the device may remain stuck on firmware version 6.7.17 and fail to upgrade through the UniFi Network Controller.

In this situation, the access point may still be online and operating normally, but firmware upgrades may fail repeatedly or the device may continue to appear as if an update is available.

In this article, we explain how to resolve the U6+ firmware upgrade issue by using the recovery method shared in the Ubiquiti Community.

Issue Description

The issue usually appears in the following way:

• The UniFi U6+ remains on firmware version 6.7.17.
• Firmware upgrade attempts from the UniFi Network Controller fail.
• Manual firmware upgrade attempts may also fail.
• The device stays online, but cannot successfully move to a newer firmware release.

Before considering the access point faulty, the recovery procedure below can be applied.

Solution Overview

The solution is to connect to the device via SSH and run the Ubiquiti recovery script.

After the script runs, the device is usually upgraded to an intermediate firmware version, such as 6.7.23. Once this recovery step is completed, the access point can normally be upgraded again from the UniFi Network Controller.

Before You Start

Before applying the procedure, we recommend checking the following:

• Make sure the access point will not lose power during the process.
• Confirm that the AP has internet access.
• Confirm that the device appears online in the UniFi Network Controller.
• If possible, take a backup of your UniFi Network configuration.
• The access point may reboot during the process, so a short wireless interruption is expected.

Connecting to the Device via SSH or Debug Terminal

Open the UniFi Network interface and select the affected U6+ access point.

Then follow these steps:

1. Go to Devices.
2. Select the affected U6+ access point.
3. Open the device panel and go to Settings.
4. Scroll down and open the Debug or SSH terminal section.
5. Access the device terminal.

If Debug Tools are disabled:

1. Go to Settings > System > Advanced.
2. Enable Debug Tools.
3. Return to the device panel and open the Debug terminal again.

Alternatively, you can connect directly to the device by SSH using its IP address.

ssh ubnt@DEVICE_IP_ADDRESS

Note: The username and password may vary depending on the device SSH credentials configured in your UniFi Network Controller.

Running the Recovery Command

After connecting to the device via SSH or Debug Terminal, run the following command:

curl -fs https://dl.ui.com/firmwares/uap/jw/U6Rescue.sh | sh

Once the command is executed, the device downloads the required files and starts the recovery process.

During the process, you may see some warning messages in the terminal. Some umount related warnings do not necessarily mean that the process has failed. After the recovery process, the device may reboot and the SSH session may be disconnected.

Post-Recovery Check

After the device reboots, wait until it comes back online in the UniFi Network Controller.

Then check the following:

• Verify whether the firmware version has changed.
• In most cases, the device will move to an intermediate firmware version such as 6.7.23.
• Once the AP is online again, start the normal firmware upgrade from the UniFi Network Controller.
• After the upgrade is completed, confirm that the device is running the latest available firmware.