Install failed with RE200v3 (fw:1.1.3)

I tried to install OpenWRT on RE200v3 but could not do so from the firmware update screen of the WebUI.

The following topic said I could downgrade the firmware, but firmware 1.1.0 seems to be missing from the official site.

If the firmware cannot be found, is the only way to install it directly from the serial console?

I got mine flashed a few months ago - let me check notes regarding the process… will edit this post over the weekend