Saw some recent posts in older thread on eSATA ExpressCard problems (MacBook Pro 17in) and wanted to list some reminders from the past. Most eSATA ExpressCards require OS X drivers (many low cost cards are SI3132 based). If you do a clean install or upgrade your OS, you'd have to reinstall the drivers. (As mentioned several times over the years, OS X upgrades usually remove the SI3132 drivers as 'incompatible' although a reinstall usually worked. And check for driver updates of course.) I had one natively supported eSATA Expresscard but it had some intermittent data corruption problems at least with some systems. (Notes/warnings to verify checksum on file copies some years ago on the Expresscards page.)
The most recent problem post there didn't mention the eSATA card model or OS version, or if he'd done an OS X clean install when getting his 2011 MacBook Pro motherboard replaced. (Via Video/GPU warranty extension program I assume.) Just guessing but he may have erased the drive (and then a clean install) before the repair and then afterwards was unable to restore his backup since it sounds like he used the eSATA ExpressCard for backups using CCC. (Later posts raise the question if the replaced motherboard might have an ExpressCard slot problem.)
Also some eSATA cards don't support port multiplier enclosures. (And enclosure bridges have sometimes been a source of problems, although the most recent post indicated he had used whatever model he owned OK in the past. The last eSATA case I used was straight SATA - no combo bridge.)
MicroSnitch 1.1 release notes
(with info on bug in OS X Yosemite affecting ability to detect Facetime camera use on some newer mac notebooks)
Professional grade, 4-bay enclosure with dual Thunderbolt™ 2 ports and RAID-ready (including RAID5), perfect for meeting demanding workflows of users. Reliable, Versatile and Capable. Up to 32TB Capacity (RAID model). Or add your own Drives with a Thunderbay 4 Enclosure Kit.