Microsoft planned to fully release the Windows 10 October 2018 Update in, well, October. That didn't happen. Shortly after it started rolling it out, people who manually installed the update, also known as Windows 10 1809, discovered various file system bugs that prompted Microsoft to delay the update's official launch. The company ended up missing the update's namesake month entirely and finally re-released it on November 14. But it turns out it's still flawed and is even unusable by certain AMD and Trend Micro customers.
File Explorer Issue
ZDNet ran down the ways in which Microsoft has yet to fix the Windows 10 October 2018 Update. The biggest issue is that File Explorer reports mapped network drives as being broken, even if there's nothing wrong with them.
Microsoft acknowledged this issue and shared a few workarounds, but unfortunately, those hackney solutions could lead to more problems for businesses that depend on their mapped network drives. The company said that "Mapped drives may fail to reconnect after starting and logging onto a Windows device" and that it "is working on a resolution and will provide updates in the 2019 timeframe." In the mean time, businesses will have to use Microsoft's workarounds and hope for the best.
But at least those businesses have a choice regarding whether or not they want to install the Windows 10 1809 update. That option hasn't even been made available to some consumers because they're using software or hardware that isn't compatible with the update. (As opposed to the "always-connected" laptops that shipped with a version of Windows 10 that was never meant to support them just so they could reach holiday shoppers.)
Incompatibility With AMD, Trend Micro
The problem lies with Trend Micro's OfficeScan and Worry-Free Business Security software, as well as AMD Radeon HD 2000 or HD 4000 series graphics cards. Trend Micro is working on patches to improve compatibility with Windows 10 1809, but until they're ready, its customers won't be able to install the latest version of Windows 10. Microsoft is actually blocking the update on those devices until Trend Micro gives the go-ahead.
Microsoft's doing the same for people with affected AMD graphics cards. Folks with an AMD Radeon HD 2000 or HD 4000 series card might notice performance issues on the lockscreen, find that Microsoft Edge flat-out stops working, or get the "INVALID_POINTER_READ_c0000005_atidxx64.dll" error. Those are old graphics cards, sure, but it's still surprising Microsoft would ship Windows 10 1809 with flaws like that.