Copying files to USB drive results in a blank file

Is it a pen/flash/thumb drive? (Manufacturer?)

Does it end up for all files blank, irrespective of type and size of file?

Does this happen only in your user account? or any user? and safe mode as well?

Have you tried to copy from a different Mac?

henrybros wrote:

I've been trying to copy files from my mac to my USB drive (128GB, Mac OS Extended (Case-sensitive, Journaled) format) but the resulting file ends up being a completely blank file; opening it in hex editor reveals that all bytes are 00.

Any idea on what's happening?

Feel free to ask anything if you need to know something before giving a solution.

Try a different USB flash drive

Hey Henrybros!

Strange one, so the same result on two different external disks, both formatted differently, in safe boot, (And on another user?),

I know it doesn’t matter what file type now, but how about the location that you’re transferring from? If from another location, even a cloud service, any difference?

Does it react the same in an external disk as NOT (case sensitive)?.

Since you were able to test on another drive. If possible, can you test the read/write privileges, and connect two separate external drives.

Mac

External 1

External 2

Can you open the files after transferring from:

Mac to external 1

Mac to external 2

External 1 to Mac

External 2 to Mac

External 1 to External 2

External 2 to External 1

Can you “Get Info” on the main HD, and both thumb drives to show the “Permissions” And formatting and space of all?

Have either been previously used, for Time Machine or some other specific function?

It may still be a good idea to reset the firmware, specifically the SMC and NVRAM, (If you haven’t already).

If it’s the exact same result in both external drives, safe boot and another user, and the time/date/region is correct, I’d:

Disconnect all external drives.

Boot to recovery mode with Command R

Open Disk Utility

Select View > Show All Devices

Then select all the internal disks and volumes running “First Aid” on all, starting with the SSS/HDD, then the Container them the volume’s (Macintosh and Macintosh Dada).

If it finishes okay, restart and test, if not, as said before, a Reinstall may be a good idea, or if need be, backup/erase/reinstall.

I think another important question may be the hardware specs of your Mac.

Sounds like the USB stick might be drawing too many mA.

Is this only text files? Are jpegs OK?

If you send over a compressed folder and uncompress it on the usb drive is it OK?

Do these files have a valid extension? i.e., .txt, .csv, .rtf?

does it happen if you use cp in the terminal?

If it does, I would say you have to re-install the OS.

Try running the last combo updater for your version of Mojave.

Are you able to create a text file in usb drive from terminal.

Like using any text editor vi/vim/nano/emacs etc…