3140970 - SAP Marketing Cloud - Forms reCaptcha integration failing due to invalid domain error

A landing page or form with having a captcha element integrated failed with a technical error. On opening the form the following error is raised:

ERROR for site owner:
Invalid domain for site key

Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.

• SAP Marketing Cloud Edition

1. Create a Form with an embedded Captcha element
   
2. Test the Form
3. Observe the following error
   

There are different reasons for that error. This is raised when either the side key is no longer valid or when the website domain is not registered in the site key settings.

• Settings inside the Marketing Cloud Tenant
  
  
  • Verify the Certificate imported to the Maintain Certificate Trust List app 
    
    Please refer to the following KBA for further information:
    
    3053003 - SAP Marketing Cloud - Landing Page Captcha Integration not working
    
    
  • Please verify the Secret and Site Key in the Communication Arrangement created for communication scenario 'Marketing - Captcha Integration ' (SAP_COM_0584)
    
• Settings in the Google Admin Console
  
  
  • Verify the domain entered for the reCAPTCHA integration
    The domain must exactly match the SMC tenant URL

Please also refer to the online help:

Setting Up Captcha Configuration for Forms

reCAPTCHA, captcha
Landing Page, Form
Landing-Page, Formular
Page d'arrivée, Formulaire , KBA , CEC-MKT-LPC , Content Studio: Landing Pages and Forms , Problem

SAP S/4HANA Cloud Public Edition all versions ; SAP S/4HANA Cloud all versions