By default browsers don't display any error messages when things go wrong. This is so your experience browsing the web is smooth and not interrupted with lots o...
There's another error, when you install an APK from a website that contains a game created in C3 it doesn't download to work offline, you always need to have active internet conection to make the game works.
I upload my game on Netlify service and everything goes good, until I try to save the game on cache to play it offline
P.D: My website is https certificated.
Android apps (APKs) definitely work offline - they don't actually load anything from the Internet.