USB shows 0 bytes? External hard drive shows 0 bytes? 0 bytes in Used space, Free space as well as Capacity? Windows prompts to format it before use? File system becomes RAW...
https://www.minitool.com/data-recover...
In general, if you encounter 0 bytes drive, you can turn to MIniTool Power Recovery to recover lost files. after recovering 0 bytes files, you can format the 0 bytes drive to use it again,