„Please provide the direct download link to QuTS hero h5.3.1.3292 IMG for TVS-h674T. The site keeps offering TS-X74…img which is wrong for my model.“
Are you saying QNAP normally provides a special Thunderbolt firmware? Otherwise your TVS-h674T is a X74 NAS
https://download.qnap.com/Storage/QuTShero/TS-X74/TS-X74_20251024-h5.3.1.3292.zip
Just to confirm: the TVS-h674T is correctly categorized under the TS-x74 series. The files provided are the right ones for your model, so no need to worry! You’re safe to proceed.
On a related note, we’re curious: Is there a specific feature in OS 5.3.1 you’re interested in that’s prompting the update question? Knowing what you’re looking for helps us understand your needs better!
Solution was here
User tried to upgrade from QTS to QuTS, hence the error