Red square appeared below the SEND button

Has to ask again for support since you marked my request as resolved but it’s not (as same for many other users)

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Dear Support Team, I’m issuing a bug with CF7 plugin .. since few days a red square appears below the SEND button.
The tag is:
<div class=”wpcf7-response-output wpcf7-display-none”></div>
Can you please help me?
Thanks,
Grace

The page I need help with: [log in to see the link]