A couple of days ago, Microsoft's Gabe Aul revealed that Windows 10 Mobile build 10536 was the latest candidate for release to the Windows Insider program. Yesterday, he said the new build would roll out today, but unfortunately, those plans have now been ripped up.

Aul said today that an issue was discovered in 10536 that would have made it impossible to properly install future builds over it:

I have some bad news folks. We discovered an issue late last night that would have caused builds *after* 10536 to not install over it. — Gabriel Aul (@ GabeAul ) September 11, 2015

He explained that the problem was "caused by our UpdateGen process which enables the build-to-build deltas" - and clearly, it's a problem that was best caught before the build began to roll out.

However, this does mean that build 10536 won't be rolling out today - and in fact, it won't be rolling out at all. As we previously reported, Windows 10 Mobile builds can't be patched in the same way that Windows 10 on PCs - so when a bug or issue is discovered in a build, a new one has to be compiled and tested internally.

There is some good news though:

@GabeAul The good news is we were already flighting the next build which has the Store fix, so we have that one close behind. — Gabriel Aul (@ GabeAul ) September 11, 2015

As Gabe says, Microsoft has already been testing the next build beyond 10536 internally (the 'Store fix' relates to an issue previously identified in that specific build). 10536 had made it down to the internal Slow ring, but whatever is currently on the internal Fast ring may well be the build that eventually makes it out to those on the public Windows Insider program.

But that's where the bad news comes in: Microsoft won't be pushing out a new build until next week, so for now, you'll have to make the most of 10512 over the next few days.

By the way, for those keeping score, it will be one month tomorrow since build 10512 was released. Given that the OS is now weeks away from launch, there may not be time to roll out many more previews before the 'RTM' build is finalized.