Actually, the only solution was to run the installation exe file as administrator. Otherwise it returned the error message mentioned in my previous post. A rather easy fix, as it turned out.
Just out of curiosity, what is your Windows operating system?
AFAIK the WebView2 Runtime has not been a component of my MS Edge browser since November 2024, and it is now a persistent component of all Win 10 and Win 11 operating systems - see announcement in the 14-Nov-2024 release notes <here> for MS Edge 131.0.2903.48. I assume this was done because many Win 10 and Win 11 users who performed a forced uninstall of MS Edge were damaging other third-party software that still required the WebView2 Runtime to run correctly.
Even if your app uses the Evergreen distribution mode, we recommend that you distribute the WebView2 Runtime, to cover edge cases where the Runtime wasn’t already installed.