You cannot make this document change

What causes this issue?

You are using the Funds Management module. You are trying to delete
table FMIOI in a purchase order or purchase requisition. This is not
possible because:
A fiscal year change has been carried out
Locking entries exist

System Response

You cannot store this document.

How to fix this error?

Delete this document line and create a new one.

Error message extract from SAP system. Copyright SAP SE.