Unable to reply all to <undisclosed recipients> email

Unable to reply all to <undisclosed recipients> email

Hi, currently new to Zoho Mail. So I just had an email from my employer which I had to reply the email with "reply all" option. However, my employer had sent the email with Bcc, thus making the cc filled with <undisclosed recipients> address. So, when I tried to send the email, Zoho gave me error message "invalid email." 

Any idea or work around to this issue? I have to sent the email by the latest tomorrow.