I've noticed this several times now, and I realize it's a problem. When transferring large amounts of files(40gb+) to a different hard drive, it randomly disconnects my 8-bay hard drive chassis. When using regular windows explorer transfer method, it doesn't seem to occur.
I can replicate the problem, but opus doesn't crash completely. It just freezes the transfer and I have to manually end the process.
That must be a bug in the bay or the drivers it uses. (We would have hundreds of complaints otherwise.)
Turning off non-buffered IO, or changing the copy buffer size, may help avoid triggering the bug. Both settings can be found under Preferences / Miscellaneous / Advanced. If you type copy into the search box at the bottom of the Prefs window it will highlight them in the list.
What type and model of drive bay is it?
Mediasonic ProBox 8 Bay External Hard Drive Enclosure - USB 3.0 & eSATA
(mediasonicstore.com/servlet/ ... Bay/Detail)
It only started occurring recently.
Is the enclosure's firmware up to date?
And your USB3.0 / SATA drivers (as applicable)?
The Mediasonic area for the drive has links to various drivers as well as discussion about problems/solutions with a few different firmware versions: forum.mediasonic.ca/viewforum.php?f=27
The USB / SATA drivers are what I would try first.
Since the process is actually crashing, from the screenshot in your last reply, it's worth checking to see if a crash dump has been created matching the date and time of the crash. If there is one with the right date & time, please zip it up and send it to us and we'll see if it reveals anything. (It may not, if something low-level like a driver or antivirus is crashing, but it's worth a look.)
If you haven't already, please try changing the Preferences / Miscellaneous / Advanced: copy_buffer_size setting to e.g. 1024 KB and the copy_nonbufferio_threshold to 0 (i.e. zero) to see if it helps avoid the problem. (If it doesn't, please reset them both back to their original values. There's a Reset button at the button of the Preferences page which resets the currently selected item.)
Another thing to try, since it's a crash and not just the drive disconnecting itself, is copying exactly the same files on to a local drive, in case it is something to do with the files and not the drives. (That could be cause by antivirus, for example.)