Yesterday Microsoft released yet another beta test of Windows 10 version 1607, the Anniversary Update scheduled for Aug. 2. Build 14393.0.rs1_release.160715-161 fits the pattern for final RTM Win10 builds, even though it has a significant, acknowledged bug.
According to Dona Sarkar's official announcement, which looks like a Cliff Notes version of a build release:
We are aware of certain cases in which Surface Books and Surface Pro 4's may bugcheck (bluescreen) due to a camera driver issue. An updated driver will roll-out via Windows Update soon that will fix this.
Brad Sams at Thurrott.com suggests treating the bug with care:
Once the driver is released, this should fix the issue but for now, it's not worth upgrading from 14390 as this will impact the stability of the install for those users.
Those of you who have been struggling with Surface Book and Surface Pro 4 bugs since their original release may no doubt take the advice in stride.
I've heard that Microsoft has since compiled a new build, 14394, which has not been widely distributed. Some take that as an indication that 14393 will not become "the" Windows 10 Anniversary Update. Many have forgotten the genesis of version 1511 build 10586. Microsoft actually compiled a build 10587 but never distributed it to the outside world. Instead, 10586 rolled out on release day, and it was immediately accompanied by a Cumulative Update -- CU No. 1, in fact -- that brought the build number up to 10586.3.
It's anybody's guess whether Microsoft will use the same sleight of hand for the release of version 1607. Last time it worked, although some users were confused for a while.
I'd be willing to bet at this point that build 14393 will likely be RTM.