Contact form 7 error om form submit when using recaptcha

Hello
I have added the “Contact form 7 recaptcha” in contact form 7 Getting the following error “There was an error trying to send your message. Please try again later.”
But when I removed the captcha from the form. Form is working fine and sending the email.
I think there is a problem with “Contact form 7 recaptcha”.
Please help me to resolve this as I am loosing my client.
Any kind of help will be appreciable.

Thanks & Kind Regards