Sounds like it might be a USB connection/hardware error, which is extremely common.
Next time it happens please take a copy of your kernel log and send it to us: dmesg > dmesg.txt ** Changed in: nautilus (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to nautilus in Ubuntu. https://bugs.launchpad.net/bugs/1782585 Title: nautilus slice error copying files To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/1782585/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs