Issue With Spring: There was an unexpected error (type=Not Found, status=404)

I believe your issue is related to packages. Your application is defined in com.organization_name.webservices.application. I am guessing your other classes are in a different package that is not a child of com.organization_name.webservices.application. Spring will automatically load controllers that are in the same package or sub-packages, for example:

com.organization_name.webservices.application
com.organization_name.webservices.application.controllers

But not packages like this:

com.organization_name.webservices.controllers

You can fix this by either moving your controller (or application), or adding ComponentScan to your Application:

@SpringBootApplication
@ComponentScan(basePackageClasses=GreetingController.class)
public class Application {

You should be seeing this in your log:

 Mapped "{[/greeting]}" onto public com.organization_name.webservices.xxx.Greeting com.organization_name.webservices.xxx.GreetingController.greeting(java.lang.String)

seems like you are missing thymleaf dependency. Put this inside your pom.xml dependencies

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

in pom.xml add the following dependency

     <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
    </dependency>

    Adding these dependencies helped me :

<dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.6.1</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.6.1</version>
            <scope>compile</scope>
        </dependency>


@EnableSwagger2
@Configuration
public class swagger {
    public Docket productApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.basePackage("com.example.Mongo"))
                .paths(regex("/mongo.*"))
                .build();
    }
}