Things currently broken:

• Windows 10 taskbar
  • The presence of 42537950 ("DisableWindows10Taskbar") feature flag causes the old taskbar to crash when being loaded. Due to this the stock Windows 10 taskbar is now no longer an option on 26002+.
  • Builds 26244 and 261x0.1252 have removed the old taskbar code altogether.
  • The reimplemented taskbar has been released for 22H2, 23H2, and 24H2.
  • Old battery flyout crashes ShellExperienceHost.exe when triggered. Fixed in upcoming 70.0
  • Programs that use tray icons to make notifications show up in notification center as "Microsoft.Explorer.Notification" without icons.
  • Following issues are now resolved with the reimplemented taskbar:
    • Right-click End Task not functional with Windows 10 taskbar style #2812
    • [24H2] Task Manager context menu option on taskbar does not function #3021
• Windows 10 start menu
  • 22621.3374 StartUI.dll (or any other version) needs to be downloaded and placed at C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartUI.dll first in order to work.
  • Does not position correctly when the taskbar is not docked to the bottom. Fixed in de2532d
  • Builds 26252 and 22635.3930 removed resources for the Windows 10 start menu, it will fail to launch there.
  • Works with EP 66.4 with no manual steps, for now...

Further new-in-24H2 and newer issues may be discussed in here, but please refrain from creating new individual issues for now.