Hello ​@neha_kumari 
Thank you for reaching out, and welcome to the Docusign Community! We appreciate your question and assure you that we are fully committed to providing you with the best service possible. 
The error message you encounter means that there is at least one Pre-fill field on your document that has not been filled in. Pre-fill fields are a special kind of sender field that allows you to enter a value or other information into your document before sending. If they are added, they must be filled in to send the envelope.

For your reference, you may check this related article. Pre-fill Document Fields 

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Best regards,

Ma. Cassandra | Docusign Community Moderator

"Select as Best" below if you find the answer a valid solution to your issue

Hello ​@neha_kumari 

How are you? I'm checking in to see if you still need assistance. If yes, kindly reply here with more context or confirm if the issue has been resolved. 

If you run into any problems, we're happy to help with those here. Wishing you a smooth rest of your day!

Ma. Cassandra | Docusign Community Moderator
Mark as “Best Answer” if this helped clarify things.