Formatting the pendrive

Have you checked how it shows in Disk Management? Is it in RAW file system? Honestly, when your pen drive is detected as RAW file system, in order to let the unsupported RAW file system be converted back to NTFS or FAT, the computer often will ask you to format before any drive access. That's also why you cannot access your data and also get 0 bytes used space and free space,
In order to access your pen drive data smoothly, you are supposed to firstly recover inaccessible data from RAW file system pen drive before you really start to format it from RAW to NTFS or FAT32.

Plug it into another usb socket and you should find it works, Sometimes usb sockets and drives can become corrup.. by right when you reboot you machine it will revert back to normal