Hi, I recently came across a late 2013 Mac Pro that had been unopened from the factory when they had OSX 10.9 (I assume pretty old then) and the computer works fine. Icloud, imessage, and such all work. However, the serial number on the bottom and inside the software does not bring anything up on apple's check coverage thing. At first I thought it may be stolen, but it would still show something when I look it up. I called apple support and they told me to take it to an apple store to get it looked at. Any ideas on what could cause this/ or should I bother taking it in? Thanks in advance.