To keep this entry a reasonable size, I’ll focus specifically on the Flex handling of errors (synchronous) and won’t address Flex handling of error events (asynchronous).

How to use the exception handling middleware in ASP.NET Core to handle errors gracefully in your minimal API applications.

To remedy this, Proxino uses a fallback technique — if Proxino goes down, you’ll simply start serving your JavaScript app from your own server as your normally would.