I have this error when trying to remind the activation key :(
{Image containing personal details removed for security}
There is a know problem and the online lookup tool can't currently find certain licence keys.
They are working to fix it so that it will be able to find all keys again.
In the meantime please contact support by sending an email to support@ccleaner.com and ask them to look your licence up for you.
PS I have removed that image for your security, it contained your email address and it is never a good idea to put that in plain view where potential spammers could see it.