14 DAY TRIAL // Microsoft rolled out Windows 10 cumulative update KB3124200 earlier this week to bring a number of undisclosed improvements on computers running the new OS, but it turns out that this patch fails to install on some PCs.
Redmond is yet to publicly acknowledge the issue, but posts on the company's Community forums confirm that there's indeed a bug in this cumulative update and installing it is impossible for certain users.
This isn't the first time users are experiencing problems with Windows 10 cumulative updates and just like before, KB3124200 fails with an error message that says very little about the cause.
“Undoing changes”
Basically, every time impacted users are trying to install this patch, they are only getting an error reading “We are unable to complete the update. Undoing changes,” before the PC restarts and gets back to the desktop.
“I have over the past 3 updates, tried all sorts of ways recommended to get an install but everything fails. As I have Windows 10 Home I cannot stop the installs repeating. I am still stuck in a never-ending loop of download, install, failure,” one of the users whose computers got impacted by the bug posted.
Some Microsoft customers tried to contact support staff, but there are cases where not even company engineers can solve the problems, so it's pretty clear that the software giant itself needs to look into this and, if necessary, provide a fix.
For the moment, there doesn't seem to be a workaround available that could help users successfully install the patch and the chance are that it will never be one. Similar problems have been experienced with previous cumulative updates as well and Microsoft has never provided a fix, so it's hard to believe that KB3124200 will be the exception.
On the good side, if you can't install this update but you will be able to deploy the next one, your computer will be fully up-to-date thanks to the new “cumulative update” approach that includes all previously-released fixes in every release.
Update: here are some instructions to fix the installation issues with this CU.