My drive stopped mounting in my Mac. What should I do?

Open Disk Utility (Applications > Utilities) and click View > Show All Devices. The drive should appear in the left column under External. An indented item should appear below it. If the item is greyed-out, it indicates possible corruption. Click the item and select First Aid to repair the volume.

If it does not repair successfully, and it is formatted as exFAT, connect the drive to a Windows computer. A corrupted exFAT drive can almost always be repaired in Windows. Simply connect the drive and right click, select Properties > Tools > Check > Repair.

Note:
We recommend formatting the drive as APFS if using OS Sonoma 14.x. (please note, this will delete all data).