Demand Header Locked

We have orders coming into Demand Entry and there’s a displayed message that says “Locked Demand”.

I’m not sure what’s causing this issue and I don’t see anything on the log.
Actions>Demand Header>Log

What steps can I take to troubleshoot this issue?

Have you looked at the Demand Workbench?

Not a very helpful message on the Demand Workbench.
“Demand Header is Locked”

We just went live and haven’t implemented our EDI yet. When we were testing I remember this happening and I cannot remember why. I’m sure I’ll come across it next week as we start it up. Is this the first time it has happened?

Have you looked at the demand contract? There are some settings in there for locking.