Cannot complete a sprint - issues are closed status?

[Deleted user]

I'm trying to diagnose why a Sprint cannot be completed - The complete Sprint Option is not available. I've checked these issues for the user and the issues and all clear:

• You don't have the right permissions: You must have the JIRA 'Project Administrator' permission for all project(s) with issues included in the sprint to complete it. If you cannot complete a sprint, check whether your sprint has issues from a project where you are not a project administrator (see this article if you need help).
• One or more of the completed issues in the sprint have sub-tasks that are not complete: You must complete the sub-tasks for all completed issues before you can end the sprint. Note, completing a sub-task means that it is in a status that has been mapped to the rightmost column of your board (see Configuring Columns).

I DID notice that all the issues in the given sprint that cannot be completed have a Closed status. The resolution is Done, but the issue is closed. 

Is this what's causing the "complete sprint" option to not be available? Can I do anything about it?

[Deleted user]

Update: JQL showed one issue that is supposedly in this project (Although - it's in a completely different project, HOWEVER, the board that issue appears on is a different board, I checked the sprint IDs and they vary. There's no link between this one issue and the sprint that cannot be closed. 

There are sprints that share names.

[Jobin Kuruvilla [Adaptavist]]

Depending on the version you are on, you might need Manage Sprints permission in the projects. Status shouldn't stop you from completing sprints.