The flashing red and green LEDs, and the special firmware upgrade screen you now see, are evidence that your OBi now has a corrupted firmware image loaded on it (for whatever reason).
Log onto the OBiTALK portal, and completely delete your OBi device off of the dashboard. Wait a few minutes.
Unplug the OBi from power and from the Ethernet cable. Using a paper clip, gently depress the recessed reset button on the bottom of the device until you can feel a click. Plug just the power cable into the OBi while continuing to hold in the reset button (requires some dexterity, or get a friend to help). Wait at least 10 seconds, until the power LED starts blinking. Release the reset button. Wait... give it time for the factory reset to attempt completion; Five minutes would be fine. It will likely still show the alternating red/green power LED. Plug the Ethernet cable back in.
As I mentioned above, download a fresh copy of the firmware, and enter the file location on the firmware update page you posted, and click the button to upgrade. Again, be patient and wait.
If this doesn't fix it, then it has a hardware failure that can't be fixed. You'll need to buy a new one.
Looking at
amazon.com, it appears that the 100 devices are out of stock, and are currently only being sold by third party sellers. Do not buy from them. Wait until it's available again, directly from Amazon, and not from a third-party.
The 200 devices are in stock, but you need to click the link in "Note: Available at a lower price from other sellers, potentially without free Prime shipping." to see the direct-from-Amazon choice.
Hint: Amazon "Prime Day" is coming up soon, on July 12th. It would be worth waiting to see if an OBi model goes on sale.