I've been using my external harddrive (Samsung T7) for over 6 months and it suddenly stopped working. It won't appear on my desktop like normal. However, while it appears as an external harddrive on Disk Utility, it says "Not Mounted."
I tried downloading the Samsung Portable app and the drive shows up, but it says "Failed to check free space or failed to locate volume"
I am having exactly the same issue, I downloaded the latest version of PSSD software on my MacBook Pro M1, no luck.. the message 'Failed to check free space or failed to locate volume' still shows.... I even tries disabling the security features on the T7 , and I am unable to access the drive. See below Image