Post-Maverick upgrade, now my firewire MyBook does not mount

[countryman]

This external firewire MyBook worked fine and continues to work fine if I boot up Snow Leopard.  However, if I boot up into Mavericks then the MyBook will not mount nor become visible in Disk Utility.  I am not running nor have ever run any WD software and so it is not related to that issue.

TIA

[ccontreras]

Mavericks caution, upgrade your WD Drive Manager to the latest version available. 

http://community.wd.com/t5/External-Drives-for-Mac/External-Drives-for-Mac-Experiencing-Data-Loss-with-Maverick-OS/td-p/613775

I hope that is only formatting issue … and that is not an old version of WD drive manager have deleted your data :cry:

in case of problems on mac OS format (when Disk Utility does not work properly), can be solved using DiskWarrior.  http://www.alsoft.com/diskwarrior/