All data gone on My Book Studio II

WD External Drives External Drives for Mac
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Same to me. All data are gone after installing the Maverisks. I can read the content after installing Maverisks. But after I start my iMac tonite, all data are gone. But, the data in other WD external disk are still there. Only the one with raid 1 are gone.

I have many years photos there. All are gone?  ><‘’‘’