How did you downgrade to firmware 1.30. I'm on Linux Mint and the latest firmware update made my K95 RGB stop working completely when I'm in Linux (even with ckb installed).
I've looked through my CUE in Windows 10, but there doesn't seem to be an option to downgrade in it, and the only option relating to firmware is an "Upgrade firmware" button (and I can't use that to downgrade because I can't find an image of the 1.30 firmware anywhere).
The only reference to downgrading firmware seems to be this thread on here, except that thread only links to old versions of the CUE software, with no links to the firmware (even though there is a warning to downgrade the firmware before you downgrade CUE).
