What is error RG45?

My friend was trying to create an account yesterday but it wouldn't let him. It kept coming up "The server failed to create your account. Error RG45."

What does this mean? 

Probably just an error, will most likely be fixed soon.

Message a moderator to check.

Okay I will, thanks.

I haven't seen that message before - there's a number of possibilities, but only the Support team could give you a definite answer: try Help --> Ask a Question --> Contact

David, moderator

Okay, thank you.

i just cleared my browser cache and was able to log in

Really?

me too

https://support.chess.com/en/articles/8583549-i-m-getting-error-code-rg45-what-should-i-do

This error means that your friend has been IP adress blocked. This most likely happened because he has had accounts that have been previously banned, and he can no longer create any more