However, this September update apparently introduced a plethora of other bugs that needed unscheduled, non-Patch Tuesday patches (known as “out-of-band” fixes) to resolve. Some bugs, especially for older Windows systems, don’t even have fixes to this day. Here are the bugs (and the fixes) on the September update that were discovered:

Windows 10

One of the last cumulative updates for the Windows 10 Creators Update, KB 4038788, was supposed to bring bug fixes but apparently, it introduced performance issues itself. A new cumulative update KB 4040724 was then issued on Monday, September 25 to hotfix the new bugs. Another cumulative hotfix was also issued on Monday for the systems still running the Windows 10 Anniversary Update. Issues apparently appeared after this month’s Patch Tuesday cumulative update KB 4038801 was executed to resolve the problems. However, unlike the hotfix for Windows 10 Creators Update, this is not distributed via Automatic Updates but it needs to be downloaded and installed manually.

Windows 8.1

Users are reporting that after installing this month’s Monthly Rollup for Windows 8.1, KB 4038792, they can no longer log on to their PCs with a Microsoft account. Yikes! And unlike the Windows 1o, there’s no hotfix for this issue yet.

Windows 7

There’s a widely reported issue with Internet Explorer 11 spontaneously showing a search box on the address bar after installing the Windows 7 Monthly Rollup, KB 4038777, or the Internet Explorer security patch, KB 4036586. It was discovered that this was a result of IE11 under-the-hood font size changes and undocumented changes in the Tab view. Although there’s a workaround, there’s still no official patch to fix this.


Even Office had a bad security patch this September. Microsoft reportedly pulled the September Outlook 2007 security patch KB 4011086 and replaced it with KB 4011110. The bad news is that users will have to uninstall the last patch to install the new update.

Bottom line

We haven’t seen this amount of post-update bugs in a long time but overall, we have to say it – what bad form in September, Microsoft. We are hoping the company will at least address them in next month’s new set of updates so stay tuned.

More from

Equifax breach lets ID thieves have surgery on your dime This free app can detect hidden credit card skimmers How to stop hackers from using “Find my Device” to lock your gadget with ransomware