i just purchased pro key from amazon.in but key showing invalid constantly. i tried all ways to solve it but non of them are working.
Sorry to hear that you're having trouble with this; not something that can really be solved on a user forum, however. :)
Please get in contact with our support team via the Contact Us form here: https://support.piriform.com/hc/en-us/requests/new?ticket_form_id=86507 or by emailing support@ccleaner.com so that we can check these licensing details and advise further from there.
Was the key being sold by a private seller or a store? I’m wondering if the key has already been used so is showing as invalid.