For about the past 4-6 months, I’ve began having difficulties with my external hard drives - both are WD (1 is a 4TB MyBook and other is an 8TB EasyStore, both connected via USB and my 27” 2017 iMac. In short, I first noticed the issue when I would randomly get error messages saying that “Time Machine couldn’t back up to Time Machine.” When I click the details button, it really doesn’t give too much more information, just that “…unable to complete backup. An error occurred while creating the backup folder.” The drive itself still shows up in the finder as mounted and I can even click through my folders and view files. However, when I try to play a video file with an application like VLC, I get the error “The application ‘VLC’ can’t be opened. Error -36” Additionally, when I delete something from the hard drive and then try to empty the trash can, I get the error “operation can’t be completed because an unexpected error occurred (error code -50).” In other words, the drive shows up as mounted in the finder but is essentially useless, despite the fact that I can still see all my folders/files. Another complicating factor is the fact that I actually have TWO WD external hard drives connected (other one is an 8TB). This 8TB is partitioned into two portions - one that is cloned backup of my other 4TB HDD (using CarbonCopyCloner), and the other partition is the Time Machine backup. But when I get this error message of “Time Machine backup failed” that seems to be my indicator of the problem, neither drive works. The time machine won’t backup on one drive and I’m unable to play/open files on the other drive (again, despite the fact that I can still see everything through the finder). In terms of correcting the problem, the ONLY solution is disconnecting the external HDD or restarting the computer (which has “disconnecting” the drive as part of it). But I guess it is helpful to know that it doesn’t seem to require an actual computer restart and only needs the drive disconnected/reconnected. However, when I do try to drag the hard drive icon over the trash to eject it, I can an error saying it is currently in use and would I like to force eject it. I am able to force eject it, the icon goes off the desktop and the drive is ejected. The problem is that it’s only up and running/functional for about 2-3 days (sometimes more, sometimes less) and then I get that stupid Time Machine backup error. Then restart computer to lazily “fix” the problem instead of posting to this forum and trying to figure out the root cause of this problem! Should also be noted that this problem started on the last version of OSX and continues to plague me now with Mojave. So any ideas what could be going on or has anybody ever had this happen to them? Is there any utility or activity log or terminal function that I could utilize to get a “play by play” of exactly what’s going on to try and uncover this error whenever it happens? I’ll be following this thread very closely so if you need more information from me or have any questions, feel free to post and I’ll get back to you ASAP! Thank you in advance!