Could it be that it’s still claimed to another (old) account? If so, you might want to do a ‘particle identify’ in the CLI and enter that ID on the Web IDE after clicking “add device” in the devices tab. That should allow you to either claim the device, or request for a transfer of ownership to whomever currently owns it.
weird … I did add the Core ID to my web ide and everything worked just fine.
I’m able to turn the D7 led on/off from my iphone and I can flash the device from my web IDE.
now sure why I had to do this step manually … but it works just fine now