Change captcha error messages

https://contactform7.com/2015/09/17/contact-form-7-43/

Set WPCF7_USE_REALLY_SIMPLE_CAPTCHA to true.

Thanks you

You can add the following code into your theme’s functions.php file to do the same thing:

add_filter( 'wpcf7_use_really_simple_captcha', '__return_true' );