New registrations are not allowed from your IP address

A friend of mine is complaining that it’s impossible to register/login to the forum.
Is there any way to fix this?

https://imgur.com/a/pXsZwaf

Hi,

A few IP addresses were recognized as suspicious because of the severe wave of spam mesasages, and there is a chance that some shared IP address was affected as well.
If you know the address from which the registration failed, please DM me. If it is not possible, we’ll probably need to reset the blacklist.