I have used a Toshiba 1TB external hard drive on my Mac for about 6 months with no problems. Then I upgraded to El Capitan a couple of days ago and ever since then the hard drive is not recognized. I get this message when plugging it in: "The dish you inserted was not readable by this computer" with the options Initialize (takes me to Disk Utility), Ignore, and Eject. I've tried calling both Apple and Toshiba for troubleshooting and of course they were of no help. I did confirm with Toshiba that there are no updates for their hard drives as they are all plug and play. My main issue is I don't want to lose the data on the hard drive. Stupid me did not back it up anywhere so this hard drive is its only location. I haven't tried to Erase the data at all. So I finally decided I would go to Best Buy and buy a new hard drive that definitely works on El Capitan. I got home today and went to plug in the Toshiba drive to an old Mac (haven't touched it in a year so not sure what OS is on there but obviously not El Capitan). Now it is not recognized on the old computer too! I then tried it in another Mac that doesn't have El Capitan and again, not recognized. I have no idea what the problem could be since it worked perfectly fine before the El Capitan update and now doesn't work on any computer. It can't be a coincidence that it broke the exact time I updated... Here is a screenshot of the Disk Utility with the Toshiba plugged in: Any help would be greatly appreciated! I don't want to lose all that data!!!