Type this magic spell: chkdsk X: /f

That is the digital equivalent of burning down your house to check for a gas leak.

Your heart sinks. The drive’s file system has mysteriously turned —a digital ghost. Windows can see the hardware, but it no longer understands the language (NTFS, FAT32, exFAT) written on it.

Now go unplug that drive. And for the love of all that is holy, start a cloud backup today.