The solution to this could differ depending on your setup regarding your own scanning installation or your external scanning supplier.
First of all, make sure that you have no filter saved when you search for invoices in the invoice log. Click Clear before clicking Search.
If this does't help, the next step is to log on to PaletteMaster to see if the Maintenance Service Job for Invoice Capture is running properly. (If you don't have access to PaletteMaster, contact Palette's support.)
The Invoice Capture Maintenance Serivce Job in Palette Master can differ depending on installation. Look at the job and see if Last Run is today. If you notice that all jobs has a Last Run date that is a long time ago, contact your IT-department and ask them to restart the Palette Maintenance Service on your application or SQL-server. Palette Maintenance Service is a Windows Service.
If you have a external scanning supplier, it is possible that they have not delivered the invoices, or that the invoices were not delivered in time. The job in PaletteMaster is often set up to run a few times in the morning. If the invoices were not delivered before then, you can start the job in PaletteMaster manually to see if the invoices shows up in the invoice log.