This one gets me every time. I use Tuxera NTFS (note: I’ve been using https://github.com/osxfuse/osxfuse/wiki/NTFS-3G since 2015) to add NTFS support to my mac. However, every time I tried to format a USB stick to be NTFS to use in a Windows PC, every time I plugged it in Windows would tell me it needed formatting.
I eventually figured out that I’d previously used this USB stick to install Mountain Lion, and I had set the disk partition to use the GUID scheme, instead of the Master Boot scheme. Repartitioning the USB stick with Disk Utility, making sure to select Master Boot from the options menu fixed the issue straight away.