Versions didn't show and I was getting errors in the Developer Tools: `Refused to execute inline script because it violates the following Content Security Policy directive: "script-src 'self'"`. The cause is probably that Chrome has implemented extra security since this tutorial was created. Added 'unsafe-inline' and it works.
I've asked #19775 because I was frustrated with how hard it was to find a way to fix (instead of hide) the CSP warning in Electron and I complained that even the official quick start guide wasn't compliant with the security checklist at https://electronjs.org/docs/tutorial/security. Someone helped me out with a CSP meta tag which I have later noticed is indeed mentioned in the checklist, too: https://electronjs.org/docs/tutorial/security#csp-meta-tag. I have not used the checklist one verbatim because it prevents a `script` tag from working when serving `index.html` through the `file:` protocol as the quick start does. I instead used the one the person in my issue recommended which seems to work well to me. I am not that well versed in CSP so there might be a better policy to include with the quick start, but this is what I've got for now.