I keep having this issue with my drives and it's getting to the point where I think external drives are very unreliable. If anyone knows a solution to my problem, that would be great: I ejected my Seagate Backup Plus for Mac Portable Drive properly, but as it generally takes a while to eject, I went off and did some things. I came back only a few moments later and unplugged my drive, just to realize it hadn't finished ejecting properly. Now when I plug it in, it won't mount to my MacBook Pro. I can see it in Disk Utility, but it shows as unmounted. I tried force mounting it, but it said it couldn't do it (with no explanation) and suggested First Aid. I verified the disk and it said it needed repairs. I repaired the disk and it said it couldn't repair it. I have never seen this issue before, but having had an unmounted disk issue in general in the recent past, I tried my last solution. Keeping the drive plugged in, I shut down my computer. Once it shut down completely and the light on my drive turned off, I unplugged the drive. Then I restarted my MacBook and then plugged the drive back in. It still doesn't show up in Finder, but it will in Disk Utility as "unmounted". I tried force mounting again, and it still didn't work. I verified the disk again, but this time it says everything is OK. I repaired it just in case, and the repair said everything is OK. Tried force mounting once more, and it still won't mount. I'm completely stumped on this. I can't format the drive because it's my backup and has ALL of my honeymoon pictures on it (plus many other important, irreplaceable photographs). This drive is specific for Mac and I only use it on my Mac. Please, if anyone has any possible solutions, that would be great!!!