I have an Spring Boot Admin server running just fine. Here are the files:
pom.xml
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <spring-boot-admin.version>2.1.0</spring-boot-admin.version> </properties> <dependencies> <dependency> <groupId>de.codecentric</groupId> <artifactId>spring-boot-admin-server</artifactId> </dependency> <dependency> <groupId>de.codecentric</groupId> <artifactId>spring-boot-admin-server-ui</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>de.codecentric</groupId> <artifactId>spring-boot-admin-dependencies</artifactId> <version>${spring-boot-admin.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> application.properties
server.port = 9090 spring.application.name = adminserver DemoApplication.java
@SpringBootApplication @EnableAdminServer public class DemoApplication { public static void main(String[] args) { SpringApplication.run(DemoApplication.class, args); } } This works great. I can navigate to http://localhost:9090/#/applications and see the admin server just fine. 
The problem is when I try to register one of my client applications to the server. Here are the details for my client application:
pom.xml
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.0.RC1</version> <relativePath/> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-security</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-hateoas</artifactId> </dependency> <dependency> <groupId>de.codecentric</groupId> <artifactId>spring-boot-admin-starter-client</artifactId> <version>1.5.7</version> </dependency> </dependencies> application.yml
spring: profiles: default boot: admin: url: http://localhost:9090 management: context-path: /actuator When I start up the client application, I can navigate to http://localhost:8081/actuator/health and see all the health info just fine. But I also end up getting these errors in the console:
DEBUG --- [ registrationTask1] de.codecentric.boot.admin.client.registration.ApplicationRegistrator : Failed to register application as Application [name=ClientApp, managementUrl=http://richard-desktop:8081/actuator/, healthUrl=http://richard-desktop:8081/actuator/health/, serviceUrl=http://richard-desktop:8081/] at spring-boot-admin ([http://localhost:9090/api/applications]): 404 Not Found DEBUG --- [ registrationTask1] de.codecentric.boot.admin.client.registration.ApplicationRegistrator : Failed to register application as Application [name=ClientApp, managementUrl=http://richard-desktop:8081/actuator/, healthUrl=http://richard-desktop:8081/actuator/health/, serviceUrl=http://richard-desktop:8081/] at spring-boot-admin ([http://localhost:9090/api/applications]): 404 Not Found DEBUG --- [ registrationTask1] de.codecentric.boot.admin.client.registration.ApplicationRegistrator : Failed to register application as Application [name=ClientApp, managementUrl=http://richard-desktop:8081/actuator/, healthUrl=http://richard-desktop:8081/actuator/health/, serviceUrl=http://richard-desktop:8081/] at spring-boot-admin ([http://localhost:9090/api/applications]): 404 Not Found What am I doing wrong here?