The bug didn't affect all Windows 10 Anniversary installations, but Microsoft's apparent failure to address it before general release raised questions about the purpose of Insiders offering feedback during testing.
Microsoft did miss its chance to nip the bug in the bud early, but it appears public grumbling about the issues since Friday have caught its attention and the company has been working hard to resolve the specific problems.
Spotted by Neowin, Microsoft today posted on the now 30-page topic on its forums that it is putting the final touches to a script to resolve the problem.
"We've been working diligently on this issue and are finalizing a clean-up script that will fix the underlying issue preventing the install of KB3194496 (Cumulative Update 14393.222) for affected users. Your patience during our research and subsequent work is greatly appreciated," Microsoft said.
Customers who aren't happy about this update experience should probably contact Microsoft's customer support, according to the company's previous statements.
Microsoft says it does do extensive testing before releasing updates to 350 million devices and is aiming for an issue-free experience for everyone. But when it fails, it wants to hear from users so it can address those bugs more quickly.
Update, October 6: Microsoft has now issued a further statement saying it "became aware of an issue with the recent Windows 10 cumulative update that impacted a small number of customers in the Windows Insider Program that were running a previous build of the OS. We have created a solution to resolve this issue, which is now live."