Windows 10 Anniversary + Boot Camp = no longer mounting Mac partition

Same problem, earlier onset (I'm signed up to get release preview builds). Was really hoping MS was going to patch this before the wide release, but no such luck.

The latest build of HFSExplorer (http://www.catacombae.org/) works a charm for mounting, mapping, and extracting data from the HFS partition, so long as it is "Run in Administrator Mode". But as a software tool, it is somewhat inelegant compared to native access though File Explorer. Here's hoping this feature can be restored before long.

The W10 and W10 Anniversary Update breaks the JHFS+ driver loading in Windows. W7 and W8.1 do not have these issues. I have also checked that 6.0.6136 JHFS+ packages are signed, but they will not load. I need to look in Event Viewer to see what is causing issues.

If you have a business-crtitical system, I suggest staying away from the bleeding edge Windows updates otherwise you will hemorrhage. 😉

Paragon HFS+ should be checked for driver signatures. You may also want to check for events in Event Viewer.

My original tests are W7-to-W10 and W8.1-to-W10 and then Apple Software Update. Both the AppleHFS.sys and AppleMNT.sys are at 6.x versions.

I am going to try a clean install of W10 and check these again. I am staying away from the Anniversary Update.

Are you bootcamp 6? Make sure you have latest bootcamp. Running Apple Software Update will not upgrade your bootcamp.

Apple can deploy drivers through Apple Software Update, as they did in April 2016 when the AMD FirePro GL D700 drivers were updated from 15.201 to 15.301, before they reverted back to 15.200:

...but they almost certainly will not do that for file system drivers; i.e., a new package needs to be downloaded in Boot Camp Assistant in Mac OS (Applications > Utilities). The Apple HFS and Apple Mount Manager drivers are still v.6.0.1.0 and 6.0.0.0, respectively, as of today which is the same as on 23 July 2016 and both drivers still have digital sigs from 12 August 2015. The BootCamp.msi is also still v.6.0.6136 on both dates and has the same hash. Will re-post if and when that changes... hopefully I'll hear of an MS patch at work before Apple has to do anything.

I have clean installed W10 using the latest Win10_1607_English_x64.iso. There are no functional HFS drivers. I will run

Win10_1511_English_x64.iso (both the _1 and _2 versions) and test. Next test is replacing these two files from a 5.1.5621 (for my specific model - 2012 13-in MBP) distribution and testing. I also have an older BC package 6.0.6133 to be tested.

This is a W10 problem based on testing so far. Diskpart reports the partition but no volume is created/reported. The BIOS installations have the correct MBR. Either volume discovery is broken or the drivers do not support the latest builds.

Have you tried HFSExplorer http://www.catacombae.org/ as a temporary means of gaining access?

Brian Kendig wrote:

Do you know of any way to report this to Apple (and possibly Microsoft)?

I will file a bug report with Apple with a reproducible set of tests.

I don't know what method is used by the software to read the HFS partition within Windows, but the tool being open source I presume someone familiar with code would be able to deduce. It was just very reassuring for me to find that read-only access to the partition was at least possible in Windows 10 Anniversary, ruling out corruption of the Mac partition or the master boot record.

Brian Kendig wrote:

Thank you for recommending that, but right now I'm more interested in getting the previous functionality back as it was!

It's my understanding that Boot Camp uses a hybrid MBR partition table, while OSX boots straight off the GPT. I may be super mistaken, but I think one can still boot into OSX even if there's a problem on the hybrid partition table.