-- HARDWARE: Asus \ Model FA506iU
-- OS: Windows-10 Home, Version: 10.0.19042, Build: 19042
-- Microsoft Management Console (mmc.exe), Version: 10.19041.746
-- Event Viewer (eventvwr.exe), Version: 10.0.19041.1

SHORT VERSION: After using 'Find' from within eventvwr.exe, any attempt to use the 'Cancel' or the red 'X', upper-right corner of the 'Find' dialog, will cause everything, Find, eventvwr.exe and mmc.exe to hang then ultimately crash.

DETAILS:

First encountered while using the OEM's install of Win-10 Home, its included bloatware, with all available Bios\Firmware, Drivers and Win-10 Home updates installed. The behavior persists after using the Microsoft 'media creation tool' (iSO), for a Win-10 install; minus the bloatware.

With either of the above installs, the only third party software we installed:

1) iTunes, Ver: 12.11.0.26. Quick install for its iPhone drivers.
2) Video Management Software (VMS), ver: 2.0.80, undocumented code, from Swann.com

When VMS hangs/cashes, we immediately employ eventvwr.exe. Once opened, using ctrl + f ('Find' dialog), we search for 'vms'; looking for a clue. As stated above, manually attempting to dismiss the 'Find' dialog by using either the 'Cancel' or 'Close' (red x) will result in the entire mmc.exe tree to hang and crash.

We have mostly experienced mmc.exe crashing directly after VMS crashes.

-- Sfc /scannow, finds nothing
-- Attached, referenced or otherwise included in this post are exports from eventvwr.exe for both VMS and mmc.exe.

I'm hoping my post was both detailed and concise.

Respectfully