Unfortunately I don't have an e-sata to USB 3.0 converter. My guess is a compatibility issue. I can't confirm 100% but it most likely is that. The router works is virtually all USB thumbdrives and most USB drive enclosures.
arpr89:
I believe your issue is that it is formatted in a Mac format. The router can only use FAT/FAT32/NTFS via USB storage. If you are able to safely move your data off the drive and reformat using NTFS it should do the trick.