Kindly cross check and ensure you are entering the correct verification code as mentioned in the invitation email. 

Enter the code manually rather than copy-pasting the same. Also, do not copy-paste the assessment URL from any other browsers to the Google Chrome browser to access the assessment. 

In case the issue persists, please reach us out to our support number +918067414716. Also raise a ticket with the screenshot of the error. Click here to raise a ticket.