Starting with 8080 we introduced UFI images. They include the fastiron OS, boot code, POE firmware, etc. all in one .bin file. In 8080, you can run the old style images or UFI. Starting with 8090, you should run the UFI version. The old style images exist in case you are upgrading from a version that does not recognize UFI images. You should eventually upgrade to UFI. You can simply copy the UFI version (ex. SPS08090gufi.bin) and reboot to the UFI image. The message you are seeing will then go away.
Ben Beck, RCNA, Principal Technical Support Engineer support.ruckuswireless.com/contact-us