From the JIRA manual, I can read this about creating Sprints:
"Ranking is not enabled: You can only create sprints, if you have enabled ranking for your board."
What I cannot find is any explanation as to WHY?
Why would other sorting order of backlog have anything to do with the ability to create sprints??
Maybe there is an obvious answer but I cannot see it... thankful if someone can explain.
My option now is to enable ranking to be able to create a Sprint, and then disable it again, but it makes no sense.