"Invite new user": error 4280450001

You probably need to open a support ticket for this, they may need to manually remove a user registered on the device's back end through SSH/TelNet.

http://support.netgear.com/general/contact/#tab-call

Hello,
Do you have a local user with a name identical to the name of the user that you are trying to add to ReadyCLOUD? This could cause issues. Also, do you get the same error when you try to add another user with a different name to ReadyCLOUD? You could also try removing the problematic user from the ReadyCLOUD service in general through “Settings” on the ReadyCLOUD website and then create a new user with the same email address but a different username.

Bye,
Eskender

Thanks Eskender. Yes, that is it!

I have local RN users @mycompany.co.za which I've tried to add to ReadyCloud for cloud access. Adding a user e-mail that does not exist in the local user list works (eg: @gmail.com). However, this is not ideal as I'd like to give some RN local users access via ReadyCloud as well.

Thank you for your reply though. It solved the error.