Well, it’s been a long time since I had a Blue Screen Of Death (“BSOD”) and at least with Windows 10 it’s more friendly than the core dumps of the old days. It even has a smiley to help you feel better that you have just lost the document you were working on, and were about to save (why does autosave only work properly if you save to OneDrive?)
My problems started on Friday, and appeared every time I tried to print. Reinstalling the printer drivers fixed the problem, but starting just after a big security update did make me suspicious.
Microsoft have admitted the BSOD was caused by a bug in the patch, for an earlier problem that left some Windows 10 users unable to print at all after a security update.
Finally, Microsoft issued KB5001649 for Windows 2004 and 20H2, KB5001648 for 1909, KB5001638 for 1809 and so on. This seems to have fixed the problem, so I hope you are all unaffected by now; if not, do check that you are notified of Windows updates automatically.