Problem:
Purchase order Budget validation Error in Ax 2012 coming during purchase invoice . This PO is previous year purchase order on which period is stopped/closed.
Solution:
Check the option in below menu.
Go to budgeting -Setup->Budget control->Budget control configuration
and make changes in projectsourcedoucuemntlineitemHelper class of projTranstype method by comparing class at Hotfix Ax 2012 R2 KB2921204