Eclipse showing "Maven Configuration Problem: Unknown"

Question

I just imported a spingboot project that I created in https://start.spring.io/ in eclipse. I tried to import two times, but the problem persists. Already tried to do a mvn update , a mvn clean install, tried to clean the project but none of this worked. Its a problem in the first line of pom xml file. I dont have any idea how to solve this. I'm using java 11

This is the complete POM file:

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0  http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent>     <groupId>org.springframework.boot</groupId>     <artifactId>spring-boot-starter-parent</artifactId>     <version>2.1.5.RELEASE</version>     <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.in28minutes.springboot.rest.example</groupId> <artifactId>spring-boot-2-jpa-with-hibernate-and-h2</artifactId> <version>0.0.1-SNAPSHOT</version> <name>spring-boot-2-jpa-with-hibernate-and-h2</name> <description>Demo project for Spring Boot</description>  <properties>     <java.version>11</java.version> </properties>  <dependencies>     <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-data-jpa</artifactId>     </dependency>     <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-web</artifactId>     </dependency>      <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-devtools</artifactId>         <scope>runtime</scope>     </dependency>     <dependency>         <groupId>com.h2database</groupId>         <artifactId>h2</artifactId>         <scope>runtime</scope>     </dependency>     <dependency>         <groupId>org.projectlombok</groupId>         <artifactId>lombok</artifactId>         <optional>true</optional>     </dependency>     <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-test</artifactId>         <scope>test</scope>     </dependency> </dependencies>  <build>     <plugins>         <plugin>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-maven-plugin</artifactId>         </plugin>     </plugins> </build> 

Answer 1

This seems like a bug in eclipse: https://bugs.eclipse.org/bugs/show_bug.cgi?id=547340

You can fix this by temporary downgrading the maven jar plugin version to 3.1.1 from 3.1.2. Add this to the properties section:

<maven-jar-plugin.version>3.1.1</maven-jar-plugin.version> 

So your pom will look like this:

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0  http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent>     <groupId>org.springframework.boot</groupId>     <artifactId>spring-boot-starter-parent</artifactId>     <version>2.1.5.RELEASE</version>     <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.in28minutes.springboot.rest.example</groupId> <artifactId>spring-boot-2-jpa-with-hibernate-and-h2</artifactId> <version>0.0.1-SNAPSHOT</version> <name>spring-boot-2-jpa-with-hibernate-and-h2</name> <description>Demo project for Spring Boot</description>  <properties>     <java.version>11</java.version>     <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version> </properties>  <dependencies>     <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-data-jpa</artifactId>     </dependency>     <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-web</artifactId>     </dependency>      <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-devtools</artifactId>         <scope>runtime</scope>     </dependency>     <dependency>         <groupId>com.h2database</groupId>         <artifactId>h2</artifactId>         <scope>runtime</scope>     </dependency>     <dependency>         <groupId>org.projectlombok</groupId>         <artifactId>lombok</artifactId>         <optional>true</optional>     </dependency>     <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-test</artifactId>         <scope>test</scope>     </dependency> </dependencies>  <build>     <plugins>         <plugin>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-maven-plugin</artifactId>         </plugin>     </plugins> </build> </project> 

Update: A fix has been released. Click Help > Check for updates in Eclipse/STS and install the newest m2e connector.