First time I've encountered this issue...

We use Pastel Xpress V17. Suddenly this morning when I view a customer of supplier detailed ledger, I am unable to view the invoices that appear on the detailed ledger. I used to be able to click on the invoices listed, and it would open it. I haven't made any changes to settings that I am aware of... anyone had this issue before, and perhaps know how to "fix" it?

Thanks in advance