Win 10 pro gives error saying you have win 10 home key and won't activate. Microsoft in an online post advises waiting for a fix. 9 Nov 2018. My laptop did this this morning.
https://answers.microsoft.com/en-us/windows/forum/all/windows-suddenly-deactivated/fe9a4ecf-2e2a-491d-a43e-b010c316d1c4?auth=1
https://hothardware.com/news/microsoft-confirms-windows-10-pro-licenses-suddenly-deactivated
I haven't tried phoning in for activation, reckon I will just wait. (Typing SLUI 04)
https://www.forbes.com/sites/jasonevangelho/2018/11/08/windows-10-pro-licenses-are-being-downgraded-to-windows-10-home/#4d17a8cc4c9f
The reddit thread:
https://www.reddit.com/r/Windows10/comments/9v6ibm/windows_10_pro_suddenly_not_activated/