Unable to submit future dated absence dates. Error received (ANC-3405288)

I try entering in future dated absence requests and i get the following error appear:

I noticed on the screenshot it shows the projected balance as 0 but I'm not sure how to calculate this correctly or check this. I can confirm that the person record has the correct absence plan assigned to them so please kindly advise on what else i need to check or do to get this resolved. Thank you