Registration key is not valid error 12057

[neFo]

I had to reinstall CCleaner and i resend my license key to my e-mail but when i try to register it says that is not valid. I was copying and writing but none of these works.

[nukecad]

I assume that by "resend my licence key to my email" you mean that you have used the Licence Lookup facility to get it resent to you?

Check this article for the section on : "If you get an error saying that your license key is not valid:"
https://support.piriform.com/hc/en-us/articles/204043844-How-to-register-and-activate-CCleaner-Professional#if-you-get-an-error-saying-that-your-license-key-is-not-valid--0-9

If the suggestions there don't help then use the 'Contact Us' button at the bottom of that article to raise a support ticket.
Alternatively you can send an email to support@ccleaner.com describing your problem.

Licence keys are private so we cant deal with them on this public forum, but support should be able to quickly sort things out for you.