Scheduling Error Message

[RezaG7]

I am receiving the error message "You need to provide additional information. Please correct the errors below and try again" on the Scheduling page when trying to send out an email. I have read the other responses to the same issue, but my address information is 100% correct, so that can't be the issue. I have remade - not copied - the email on a separate campaign and got the same message. I even tried scheduling the email from my phone. There are no indications for where the error lies on the Scheduling page. 

[William_A]

Hello @RezaG7 ,

Some troubleshooting questions:

1. Are the required elements of the email's header filled in (from address, reply-to address, subject line, from name)?
2. Have you recently made updates to your account's email authentication that might impact the verified addresses (switching from ccsend to self-authentication, or vice versa)?
3. Does the email contain any specialty blocks that were copied over from its previous version - feedback blocks, RSVP blocks, or product blocks? 
4. If you have a specialty block like a feedback, RSVP, or product block, do they contain emojis or special characters?