Just installed OS X updates and can no longer boot into Bootcamp

Question

Just installed the latest updates for OS X Yosemite and now I can't boot to my Bootcamp partition. It doesn't show up in Startup Disks and it's not an option when booting while holding Option. The partition still shows up in Disk Utility but it no longer says BOOTCAMP, it now says disk04s. Is this fixable? I just wrote some data to that partition last night that I really don't want to lose and it hasn't yet been backed up. Thank you.
diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage                         91.0 GB    disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
   4:       Microsoft Basic Data                         20.0 GB    disk0s4
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Macintosh HD           *90.0 GB    disk1
                                 Logical Volume on disk0s2
                                 2CC4DC13-C5C7-47E8-B005-3B8080275E8E
                                 Unencrypted
sudo gpt -vv -r show /dev/disk0
gpt show: /dev/disk0: mediasize=121332826112; sectorsize=512; blocks=236978176
gpt show: /dev/disk0: Suspicious MBR at sector 0
gpt show: /dev/disk0: Pri GPT at sector 1
gpt show: /dev/disk0: Sec GPT at sector 236978175
      start       size  index  contents
          0          1         MBR
          1          1         Pri GPT header
          2         32         Pri GPT table
         34          6       
         40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
     409640  177734368      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
  178144008    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  179413544   18503128       
  197916672   39059456      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  236976128       2015       
  236978143         32         Sec GPT table
  236978175          1         Sec GPT header
sudo fdisk /dev/disk0
Disk: /dev/disk0 geometry: 14751/255/63 [236978176 sectors]
Signature: 0xAA55
         Starting       Ending
#: id  cyl  hd sec -  cyl  hd sec [     start -       size]
1: EE 1023 254  63 - 1023 254  63 [         1 -     409639] <Unknown ID>
2: AC 1023 254  63 - 1023 254  63 [    409640 -  177734368] <Unknown ID>
3: AB 1023 254  63 - 1023 254  63 [ 178144008 -    1269536] Darwin Boot
4: 0C 1023 254  63 - 1023 254  63 [ 197916672 -   39059456] Win95 FAT32L

Answer 1

Here is a table to validate your values.
GPT 3 Start
GPT 3 Size
GPT 3 End
NTFS Start
Sector Offset
NTFS Size
NTFS End
Sector Offset (MB)
178144008
1269536
179413544
179415040
1496
57561081
236976121
1
Leave your Testdisk display and start a new Terminal Window.
If you see any error messages during the following steps, please stop and post back here with the error message. The following steps have values from your Testdisk output (and you can verify) in Steps 7 and 8.
Rebuild GPT4 using start/end offsets
Sudo gdisk /dev/rdisk0
P  (print the full list of parts)
D  (delete)
4  (part 4)
N  (new part)
4   (part 4)
179415040- Start offset in bytes  (start point for Bootcamp part)
[phone]-  (Size offset as opposed to End offset)
0700     (Windows part type)
P           (print list of all parts just to see what changes will be made)
W         (Write the new GPT)
Y           (Yes! really write the new GPT)
  This will delete and re-write the GPT partition info for /dev/disk0s4.
Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes). The only values that need modifications are the Boot flags and step 6. Accept all other defaults that Gdisk offers.
Sudo gdisk /dev/disk0
P  (Print list of parts)
R   (Recover)
H (chooses Hybrid)
Partitions numbers to be hybridized: 2 3 4
Y (Good for GRUB question)
N (part 2 boot flag)
N (part 3 boot flag)
Y  (part 4 boot flag make NTFS bootable partition)
W  (Write the new MBR)
Y    (Yes! write the new MBR)
Reboot
Here is a sample Q&A from The GPT Fdisk. Notice the highlighted Press Enter/Return.
Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y
Creating entry for GPT partition #2 (MBR partition #2)
Enter an MBR hex code (default AF): Press Enter/Return
Set the bootable flag? (Y/N): N
Creating entry for GPT partition #3 (MBR partition #3)
Enter an MBR hex code (default AB): Press Enter/Return
Set the bootable flag? (Y/N): N
Creating entry for GPT partition #4 (MBR partition #4)
Enter an MBR hex code (default 07): Press Enter/Return
Set the bootable flag? (Y/N): Y
Test 1 - Does Bootcamp Volume show up in Finder?
Test 2 - Can you see files in Bootcamp Volume?
Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?
Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.