Time Machine Changed My External Hard Drive's to MBR and now I can't access it! On Yosemite, I was using Bootcamp to install Windows on a part of my internal hard drive. When, bootcamp was finished (before booting into Windows), Time Machine popped up and asked me if I wanted to use the 500GB USB external drive as a Time Machine backup disk... I told it I did NOT... Despite my answer, I'm now receiving "The disk you inserted is not readable by this computer". I have the following per terminal:

    Kelleys-Mac-mini:~ kelley$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *250.1 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS MBP                     215.2 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
   4:       Microsoft Basic Data BOOTCAMP                34.0 GB    disk0s4
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *500.1 GB   disk2
   1:                       0xEE                         500.1 GB   disk2s1
Kelleys-Mac-mini:~ kelley$ 


It's disk2 that I'm panicking about. That had ALLLLLLLLLL of my backed up client data as well as purchased software installers.  Is my data lost?  Or is there a solution someone  can PLEASE provide?  I'm absolutely scared to death this can't be fixed...
Thank you for your reply. That said, I did get it fixed. I opened the seemingly faulty drive with MacDrive in Winblows on my bootcamp partition. All the sudden, we were good! The drive opened and could be read and written to. Not sure how that happened but it’s fixed and honestly, that’s all I care about! ;)