Nothing beats a USB stick to securely use data on the go. However, those on the Mac can be problematic..
If a USB stick, SD card or external hard drive twitches on the Mac, it can have many causes. If the stick is not recognized at all on several devices, it is probably broken. Often, however, especially new devices cannot be formatted at all. Instead, the Mac reports: "The deletion failed". The reason for this is a setting in Disk Utility.
Follow our step-by-step instructions or take a look at the brief instructions .