Firmware and configurator doesn't need to match. As for now, there's no mtb100 even connected.
I've just opened the software and start creating a config from scratch (at least i tried), when prompted to choose device i selected mtb100, when presented with the list of firmware (as already shown in image, saying "Device not connected") the error appears.
If firmware 3.27.12+ is incompatible wih mtb100 then it should not have to appear in the list