USB Backup Failed - why?

I use the USB Backup feature to make offsite copies of my WDMyCloud, and I love it for that. But about half the time, the backup status shows as “Backup Failed. Please check your system settings”. Well, the thing is, the backup didn’t fail - I check the size and file count of the source folders and the destination USB drive, and they’re almost identical - if it’s failing, it’s only on one or two small files. My large System Backups are getting copied just fine. Is there any way to find out why it’s telling me that? I haven’t been able to find any sort of log that might have more detail.

I’m running the USB Backup app version 1.27 on WDMyCloud Firmware 5.19.117

Do you own a WDMYCLOUD?

If yes, see the User Manual, Chapter 12.
My Cloud Personal Storage User Manual (

My Cloud OS 5 Online User Manual (

Thanks, but I know all this. I have it set up and it works most of the time. but sometimes the backup fails, with no detail about why it failed.

can you use a manual copy of a zip file?

the times I have seen that error was when the external USB disk I was using was full.

I don’t think even having extended messages in the log file gives more information but you can try and see.

There may be other things that give that same message