https://wccftech.com/windows-10-bug-downgrading-pro-licenses-home/

Microsoft can’t seem to catch a break! The company is facing yet another issue affecting Windows 10 while it continues to scramble to address the ones that have pushed the company to pause the rollout of the October 2018 Update. The latest bug (error code: 0xC004C003) is apparently downgrading Windows 10 Pro licences to Windows 10 Home.

“All of a sudden after years of having this key which was from windows 8 pro then migrated to windows 10 for free, I got a notification saying my key is Windows 10 home version and that I need to install it,” one user posted on Reddit.