In the last two days we've had reports from two separate customers that DVD's no longer play on Windows 10 based devices, where previously they have.
Given that we still think Windows 10 is still an operating system to avoid and we are predominantly a business to business organisation, our customers exposure to this particular problem is limited.
Our initial hunch is that this is yet another buggy update by Microsoft that has caused this issue however there seems to be some confusion as to whether a DVD player is included with Windows 10 at all.
One recent update (KB4015438) includes "Addressed a known issue with KB4013429 that caused Windows DVD Player (and 3rd party apps that use Microsoft MPEG-2 handling libraries) to crash." and so we're confident this problem is related.
The point, however, is moot, don't bother with the Microsoft technology, instead we'd recommend VLC Media Player, from here:
The VLC software includes "no spyware, no ads and no user tracking." which is more than we can say for Windows 10.
Also available on Linux and Apple platforms.