You also might want to consider updating your VC++ 2015-2022 redistributable. Anything after VS2015 is supposed to be compatible, but perhaps something in an older one can trigger issues.
Sigil only attempts to install the redistributable if it's missing, or really, really old. Otherwise we leave that up to the user.
Permalinks for the latest:
https://learn.microsoft.com/en-us/cp...-2019-and-2022