Here's what's fixed, improved, and still broken in Windows 10 build 18945

Microsoft accidentally released a Windows 10 build to Insiders this week, but today we're still getting an intentional release for those in the Fast ring. Build 18945 is older than the build that some Insiders got on Wednesday, but it still packs a bunch of new features, such as the Cortana app and improvements to WSL2.

Of course, in addition to new features, the build also includes a long list of general improvements and fixes. Specifically, an issue that might have prevented some Insiders from installing new builds has been fixed:

• We have fixed the issue causing some Insides to experience install failures with error code c1900101 due to a compatibility bug with a storage driver on their device.
• We’ve made a few fixes to improve reliability when installing a Windows Subsystem for Linux 2 distro.
• We are extending Windows Defender ATP capabilities beyond the Windows OS and as a result are renaming to Microsoft Defender to reflect our cross-platform approach to endpoint security.
• We fixed an issue where Settings might crash if you selected Activation under Updates & Security.
• If your network connection is unexpectedly disconnected, the Miracast banner will now have a close button for you to use if needed.
• We fixed an issue where the Performance tab of Task Manager wouldn’t expand from a collapsed state if you double clicked on the text.
• We’ve updated the Details tab of Task Manager so if you right-click a process, Provide Feedback will now be listed after End Task and End Process Tree (rather than between).
• We fixed an issue where the network icon in the taskbar might show that there was no internet, even though there actually was connection.
• We fixed an issue impacting Windows Hello reliability in recent flights.
• We fixed an issue where if you manually updated the DNS server settings in Settings, it wouldn’t apply.
• We fixed an issue from the previous two flights resulting in mobile hotspot unexpectedly turning off if enabled.
• We fixed an issue that could result in the system hanging after resume from hibernation.
• We fixed an issue potentially resulting in the error, “MMC has detected an error in a snap-in and will unload it.” when you try to expand, view, or create Custom Views in Event Viewer.

Notably, there are still some known issues with this build, some of which we have been seeing in the release notes for months at this point. Here's the full list:

• There has been an issue with older versions of anti-cheat software used with games where after updating to the latest 19H1 Insider Preview builds may cause PCs to experience crashes. We are working with partners on getting their software updated with a fix, and most games have released patches to prevent PCs from experiencing this issue. To minimize the chance of running into this issue, please make sure you are running the latest version of your games before attempting to update the operating system. We are also working with anti-cheat and game developers to resolve similar issues that may arise with the 20H1 Insider Preview builds and will work to minimize the likelihood of these issues in the future.
• Some Realtek SD card readers are not functioning properly. We are investigating the issue.
• Tamper Protection may be turned off in Windows Security after updating to this build. You can turn it back on. In August, Tamper Protection will return to being on by default for all Insiders.
• Occasionally, the candidate selection in prediction candidate window for the Japanese IME doesn’t match with the composition string. We are investigating the issue.
• Insiders may notice some changes in Magnifier with today’s build. These aren’t quite ready yet for you to try, but we’ll let you know once they are in an upcoming flight.

We're still early into the 20H1 development cycle, and issues are bound to be encountered throughout the OS, even if they're not listed by Microsoft. At this point in the development, it may not be worth it for most people to install Fast ring builds given the risks. More features should be available as we get closer to the official release date of the 20H1 update.