When I do a health check, it does everything but the security issues as it says server not found....I have the pro version. [Email address removed]
Don't post your email in public like that it encourages spammers for you and the forum.
Since you have pro you can get better aid from the developers with email at support@ccleaner.com (send it from the email you registered ccleaner with so they can move you to the front of the line)
'Security' in Health check is the Software Updater for certain apps that are installed on your machine, it needs to access a server to check version numbers.
Just to make sure first - what version of CCleaner are you using?
(There was a bug in some earlier versions where in certain circumstances it would say 'server not found' even when it was found).
If/when it genuinely can't access the server that's normally because of a Firewall setting, or because your antivirus is blocking the connection.
Have you changed your firewall settings?
What antivirus are you using and what version is it at?
What Windows version do you have?