Invoice- urgent!!!

My question,

We have an invoice that shows an accounting doc was created, but when we look at the Document flow there's no Accounting document created in Doc flow? Does anyone have a logic answer for this? How come the Accounting document is not showing in the document flow?

Also when we click on the Status Overview we get the Pop Up Showing- Not relevant for FI what does that mean and why are we geting this msg?

Thank you