I have a Spring Boot app that has the thymeleaf dependency in its pom file, and an index.html in the resources/templates directory (which as I understand it is where thymeleaf looks for html files).

My controller looks like this:

```
@Controller
@SessionAttributes("game")
public class Controller {

@RequestMapping(value = "/start", method = RequestMethod.GET)
public String index( @ModelAttribute("model") Model model) {
    return "index";
}

```

I've verified that requests from the browser make their way to the index method, but then I get the following error:

```
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Thu Dec 10 20:45:21 CET 2020
There was an unexpected error (type=Not Found, status=404).
No message available

```

I also tried tinkering with the thymeleaf settings in application.properties to no avail:

```
spring.thymeleaf.cache=false
spring.thymeleaf.enabled=true
spring.thymeleaf.suffix=.html

```

I tried mvn clean, build, and install, and I keep getting a 404. Any help would be much appreciated.