Getting Error: Image Upgrade Failed. Incorrect Address Name while trying to upgrade

Hi 
Try to upgrade the device manually by following the upgrade path tool;
https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-manually-perform-a-firmware-upgrade-from/ta-p/193805
Upgrade path tool
https://docs.fortinet.com/upgrade-tool/fortigate

Hello,

I’ve seen this error before: "Image Upgrade Failed. Incorrect Address Name." In my case, it was related to an HA setup.

If your FortiGate is running in HA, especially in Active-Passive mode, it can take some time for the secondary node to fully synchronize its configuration and recognize the firmware image path or location. During that short desynchronization period, attempts to trigger an upgrade might throw this error, even if everything is configured correctly.

In my experience, the error typically disappears after a few minutes once the cluster stabilizes. It seems that the upgrade process checks the image address from both nodes, and if one is not yet aware of the image or its metadata, this message can appear even though there's no real misconfiguration.

A few tips:

• Wait 2 to 5 minutes after uploading the image before retrying the upgrade.

• Make sure the firmware server or image location is reachable by both HA nodes.

• Check that the HA sync status is healthy using get system ha status.

• If you're using FortiManager, ensure it correctly recognizes the entire HA cluster and that it's not out of sync with the current state.

Hope this helps someone else who runs into the same situation. It's a subtle behavior, but understandable when working with HA environments.