Here's a tip for anyone who owns a Ford vehicle with Sync, using a USB flash drive to play their music.
I have a 64GB Sandisk flash drive that I use to store and play music from in my truck.
Earlier this week, I formatted this drive using my Windows 10 PC. Windows 10 offers two different file systems; NTFS or EXFAT.
Since FAT32 wasn't available, I chose EXFAT.
Unfortunately, Sync doesn't recognize EXFAT devices, so plugging my flash drive into my truck generated an error message telling me that the USB device wasn't recognized.
I did some digging and found that it is possible to format using FAT32 from a Command Prompt (DOS Window). So I tried formatting the flash drive using this method. But it eventually generated an error saying that the drive was too big to be formatted as FAT32.
Back to the drawing board
After more digging, I found a piece of freeware that allows you to format various types of drives using a user-friendly interface, and also lets you choose which file system you want to use.
Long story short, I was able to format my flash drive using FAT32 and then load about 15GB of music onto it and play it again in my truck.
I hope this will help anyone else who might run into this problem. Or maybe it will help someone avoid the problem altogether!