Curl Failed Error – Ubiquiti Unifi Firmware Upgrade Failing

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Make: Ubiquiti
Model: Ubiquiti Unifi UAP-nanoHD, U6-LR, U6-Light, UAP-AC-HD, etc
Mode: CLI [Command Line Interface]
Description: In this article, we will discuss the stepwise method of firmware upgrade of Ubiquiti Unifi Access points failure due to the curl error. We get this error when we do a custom firmware upgrade via CLI. It is really important to keep the firmware of devices up-to-date. But sometimes the upgrade fails and we face issues.


Sometimes when we do custom firmware upgrades of Ubiquiti Unifi access points, it fails with a Curl error as shown below. This error is different than the “Inform Error“.

EDLEDGE-AP-BZ.6.2.44# curl -o /tmp/fwupdate.bin

% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0

curl: (60) SSL certificate problem: certificate is not yet valid

More details here:
curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.


We have already discussed a method to resolve the issue when the firmware upgrade of Ubiquiti Unifi devices fails. Refer to the below article for details.

Here we will discuss how to resolve the curl error (as shown above) which can not be resolved with the method mentioned in the article attached above.

As per the error shown above “curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it
“, because of the error the access point could not download the firmware and hence upgrade failed.

To resolve the issue, factory reset the access point and then start the upgrade in sequential order in terms of the available firmware version. Refer to the attached article to learn how to factory reset a Ubiquiti Unifi access point.

Factory reset and sequential firmware upgrade should resolve the curl error.

Other important topics on Ubiquiti Unifi Access Point

Source: Knowledge Base, Lab, Ubiquiti


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