User access to site

Good afternoon,
We have a site we are managing that we have removed a user account to test the social media login, and the ability to focus users back on to the profile page to accept the new terms and conditions and privacy policy...

Once the account was removed we cleaned the local cache, and also the site cache as we keep getting the message below.

Error
Your registration attempt has been blocked. Reason: Our system has detected that you already have an account.

The account is not in the users table, and this process to remove the account was done in CB User management.
We have since tried to reset the users account and this fails cause no such users exists on the site.

How do we resolve this one?

Duplicate registrations is based off IP Address. If it's the user attempting to register again then they've an account with their IP Address attached to it already. If it's you attempting to perform more tests then your IP Address is attached to another active account. You can disable duplicate registration protection in CB AntiSpam > Parameters > Registration > Duplicates (it's default disabled). If their/your IP Address isn't attached to another account it could be a manual block created at some point in CB AntiSpam > Blocks.