Photo by Kenny Eliason on Unsplash

I've been facing an issue with the ASP.NET developer certificates for ASP.NET Core 7 apps using HTTPS on macOS:

ERR_SSL_VERSION_OR_CIPHER_MISMATCH

Whatever I tried (dotnet dev-certs https [ --clean / --trust ]), I couldn't get it to work.

I also removed the certs manually from macOS Keychain.

Then I found this issue on GitHub which suggested adding this PropertyGroup to the csproj file:

<PropertyGroup>
  <UseAppHost>false</UseAppHost>
</PropertyGroup>

In fact it fixed the error.

Now I could use some help from you: Why does this setting fix it?