Thymeleaf 404 reports an error: there was unexpected error (type=not found, status=404)

gradle + kotlin + idea

thymeleaf 404 Error reporting positive solution

• rely on

    implementation("org.springframework.boot:spring-boot-starter-thymeleaf")
  

• To configure

    spring.thymeleaf.prefix=classpath:/templates/
    spring.thymeleaf.suffix=.html
  

• Use @Controller Instead of RestController

• Dependence is written correctly , But the library is incomplete or has problems , Need to be Reimport（ This is the hole I was in , It is estimated that the network at home is bad and I didn't pay much attention to it ok…）