You should be able to see your file before you load.
Make sure you selected the right device to load from, [UTIL] -> Set device -> then select where you want to load from.
Then when select *.pc(don't load yet) and if your program doesn't appear it's because the controller can't see it.
I would then check my device, a USB stick for example. Try another one, preferrably one with not too much storage capacity.
You also could format it.
You can find a lot of information about the storage devices on this post,
https://www.robot-forum.com/robotforum/fan…-and-usb-sizes/
I use Roboguide to translate my program but it should work the same way.
Also my first post here, hope this will help you.