Firmware veriforcation file GL-AR750S

I am trying to use the online upgrade option on my GL-AR750S-EXT and I keep getting verification fail after its downloaded.

I have tried a download and local upgrade and get the following error message “failed! ERROR: Incorrect firmware format!”

Thank you

Is the firmware format .tar? What is your current firmware version?

You can try downloading the firmware in .img format and upgrading it via Uboot. This method does not save the settings, so if you have important settings, please back them up in LuCI.

If you are using firmware older than 3.105, pls upgrade to 3.105 first.

A major openwrt distro upgrade caused this.