If you receive an error like this one when trying to fill out an E-Signature Document, it means you can no longer sign the Document.
Likely Reasons for the Closure
Closed by the Customer
The first two bullet points are things the customer may have done to close the request: For example, if a set of parents share an email address, it's possible that one of them opened the email, accessed and signed the Document, and failed to tell their spouse. There are dozens of possible scenarios like this one.
Closed by an Admin
If the request was canceled or deleted by an Admin (the last two bullet points), the customer would receive this message.
Please contact an Admin user in the company you are enrolled in to resolve this issue. Admins can see if the Document has, in fact, been signed. The Admin can send another signature request if it has not been signed.