Replying to PMs from "PM blocking" users

Someone on the forum sent me a PM, but when I tried replying back, it gave me the error message:

greensock has chosen not to receive private messages or may not be allowed to receive private messages. Therefore you may not send your message to him/her.

If you are trying to send this message to multiple recipients, remove greensock from the recipient list and send the message again.

The thing is, I’m replying to his message, and not creating a new one.

Is there any way to create exceptions for sending PMs if the user has sent messages to you?