Hey there, Xveilious.
Basically there's not much you can do, besides trying to reformat the USB flash drive with a different computer and try again. I've heard sometimes of issues with flash drives larger than 8GB, or flash drives formatted via a Mac computer. So if your flash drive is larger than 8GB perhaps you could try partitioning it in order to see if the smaller partitions are recognized and if it's been formatted via a Mac computer, try out formatting it via a Windows PC.
Hope that helps. Please let me know how it goes.
Boogieman_WD