Captcha error

I have tried to add Captcha to my site. I get this error "Input error: k: Format of site key was invalid " what does it mean and what can I do to fix it?

You did not enter public and private recaptcha keys

Yes, i entered both public and private keys.

I found another thread with this problem and tried to restart the app. But that did not help

I'm not sure whether it'll help. But try trimming entered values

How do I trim them?

Remove spaces from the beginning and end of textboxes

Hello,

I get this error, and have entered keys without spaces at the start and end as mentioned.  Any ideas? (version 2.4).  I really need this to work out as our business website is currently being hit with spam from bots (ab)using the contact us form.

Cheers

Steve

I changed my keys at captcha then it worked.