I connected my Dash Cam via USB to my Windows PC, I found it’s readable as mass storage. However, I got the “The disk you attached is not readable by this computer” error on my iMac. If I run First Aid, it feedbacks with various illegal characters and directory entries which seemingly reformat the disk. I’ve asked the Dash Cam vendor about it, no useless solutions. Does anyone have any ideas?
The file format of the Dash Cam mass storage device is not supported by macOS. That’s why the error - “The disk you attached is not readable by this computer” shows up on your Mac. Since the device is readable on Windows, check if it is NTFS formatted. If it is, the problem will be solved easily.
You can use an NTFS driver like iBoysoft NTFS for Mac to enable the NTFS device readable and writable on your Mac. If it is not NTFS formatted, follow what the Disk Utility suggests you do. You need to reformat the storage device to a macOS-compatible file system like exFAT, HFS+, APFS, or FAT. exFAT is recommended if you need to use the device on both Windows and macOS.
However, reformatting the device will erase all contents on it. If you don’t want data loss, get files off the device before reformatting. You can try to copy files from the device to your Windows computer. If you can’t do that, you can use a data recovery tool like iBoysoft Data Recovery (Download) to scan files on the device and rescue them quickly.