I reported this issue months ago and was told the same thing as other users. Our engineers are working on a solution and will push a solution as a nightly update. The only current solution is to roll back your software. Do a restore to factory settings and the hopper will recognize your hard drive again. Make sure you tell it to save timers and recordings if you have material on the drive. Of course, when you turn the hopper off you may have to go through this again.
Oy vay! I have the Hahppah 3. Tech finally got it to recognize the EHD, then after reformatting I tried to transfer a movie. It says there is no EHD! So, I rebooted. Nothing. Then I removed the EHDD and plugged it back in. Says Must reformat. Oy! Okay. Reformat. Same problem. I have software version U516. There is no way I want to roll back every day. Please fix. I have bought and reformatted three drives trying to get this to work. Also, I have an 8tb EHD I would love to use as a movieholic digital pack rat. Why the storage limit? Why a single disk for that matter? Is programming software for more than that just way hard? Seems that if you can figure out how to record 6 shows at once, this would be cake! Thanks for your help.