Can the G Drive Slim that the topic is about be repaired or does it need to be replaced?
You can erase the drive in the Disk Utility to repair corruption. It will erase the contents but afterwards it will be a clean drive you can continue to use.
You may want to try the third-party software “Disk Warrior” before you erase and reformat. The software is mentioned several times on this forum as specifically addressing problems like this.