Quote:Microsoft just updated Windows 10 to fix the file association bug we reported and some other issues. For some bizarre reason, these fixes are not available if you’ve installed the October 2018 Update on your PC.

On November 27, Microsoft released a “cumulative update” for Windows 10 that fixes a variety of bugs. As Bleeping Computer notes, Microsoft says the problem that prevents some Windows users from setting their default applications is fixed. Unfortunately, the Windows Media Player bug is still not fixed.

This update is only available for old versions of Windows 10. Specifically, it’s available for Windows 10’s April 2018 Update, Fall Creators Update, Creators Update, and Anniversary Update. The respective cumulative updates are KB4467682, KB4467681, KB4467699, and KB4467684. Windows will install the appropriate update automatically, and you can get it immediately by clicking “Check for Updates” in Windows Update.

Full reading: https://www.howtogeek.com/fyi/microsoft-fixes-windows-10s-file-association-bug-unless-youre-using-the-october-update/