LocalDate in form

I'm unable to reproduce the exact error, but I believe that adding a custom editor for the LocalDate class should fix this. Add this method to your controller:

@InitBinder
protected void initBinder(WebDataBinder binder) {
  binder.registerCustomEditor(LocalDate.class, new PropertyEditorSupport() {
    @Override
    public void setAsText(String text) throws IllegalArgumentException{
      setValue(LocalDate.parse(text, DateTimeFormatter.ofPattern("yyyy-MM-dd")));
    }

    @Override
    public String getAsText() throws IllegalArgumentException {
      return DateTimeFormatter.ofPattern("yyyy-MM-dd").format((LocalDate) getValue());
    }
  });
}

It's also possible to add this globally, you'll have to create a ControllerAdvice class and add the method there instead.

Thymeleaf provides an extra module for that: https://github.com/thymeleaf/thymeleaf-extras-java8time

Adding the following dependency (maven) should be enough:

<dependency>
    <groupId>org.thymeleaf.extras</groupId>
    <artifactId>thymeleaf-extras-java8time</artifactId>
</dependency>

Problem solved.. I don't know why but changing my template to:

<input type="date" th:value="*{date}" th:field="*{date}" />

and adding @DateTimeFormat(pattern = "yyyy-MM-dd") to entity field solved the problem.

import org.springframework.format.annotation.DateTimeFormat;

add the following annotation above date.

@DateTimeFormat(pattern = "yyyy-MM-dd")
private LocalDate date;

put additional curly bracket around date. It will convert date into string

<form action="#" th:action="@{/games/addForm}" th:object="${gameForm}" method="post">    
    <p>Date: <input type="date" th:field="*{{date}}" /></p>
</form>