APO Forecast Error now showing up

I'm trying to look at APO forecast error (Forecast Errors tab) in order to find the most appropriate model for a given SKU, but all of the metrics are blank, even after I click the STAT button.

I googled quite a bit and didn't find anything on how to get them to work. I'm quite new to SAP and APO, so I apologize if I'm missing any important info.