title: Issues with maven dependencies: UnsolvableVersionConflictException
body: <p>Im new in grpc and java.</p>
  
  <p>I have a big problem with my dependencies:</p>
  
  <blockquote>
    <p>Caused by: org.eclipse.aether.collection.UnsolvableVersionConflictException: Could not resolve version conflict among [io.grpc:grpc-all:jar:1.27.1 -> io.grpc:grpc-core:jar:[1.27.1,1.27.1], io.grpc:grpc-all:jar:1.27.1 -> io.grpc:grpc-netty:jar:1.27.1 -> io.grpc:grpc-core:jar:[1.27.1,1.27.1], io.grpc:grpc-all:jar:1.27.1 -> io.grpc:grpc-okhttp:jar:1.27.1 -> io.grpc:grpc-core:jar:[1.27.1,1.27.1], io.grpc:grpc-all:jar:1.27.1 -> io.grpc:grpc-testing:jar:1.27.1 -> io.grpc:grpc-core:jar:[1.27.1,1.27.1], net.devh:grpc-spring-boot-starter:jar:2.6.2.RELEASE -> net.devh:grpc-server-spring-boot-starter:jar:2.6.2.RELEASE -> net.devh:grpc-server-spring-boot-autoconfigure:jar:2.6.2.RELEASE -> net.devh:grpc-common-spring-boot:jar:2.6.2.RELEASE -> io.grpc:grpc-core:jar:1.25.0, net.devh:grpc-spring-boot-starter:jar:2.6.2.RELEASE -> net.devh:grpc-server-spring-boot-starter:jar:2.6.2.RELEASE -> net.devh:grpc-server-spring-boot-autoconfigure:jar:2.6.2.RELEASE -> io.grpc:grpc-netty-shaded:jar:1.25.0 -> io.grpc:grpc-core:jar:[1.25.0,1.25.0], net.devh:grpc-spring-boot-starter:jar:2.6.2.RELEASE -> net.devh:grpc-server-spring-boot-starter:jar:2.6.2.RELEASE -> net.devh:grpc-server-spring-boot-autoconfigure:jar:2.6.2.RELEASE -> io.grpc:grpc-services:jar:1.25.0 -> io.grpc:grpc-core:jar:[1.25.0,1.25.0]]</p>
  </blockquote>
  
  <p>My actual dependencies in pom file:</p>
  
  <pre><code>&lt;dependencies&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-security&lt;/artifactId&gt;
          &lt;version&gt;2.2.4.RELEASE&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-web&lt;/artifactId&gt;
          &lt;version&gt;2.2.4.RELEASE&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.session&lt;/groupId&gt;
          &lt;artifactId&gt;spring-session-core&lt;/artifactId&gt;
          &lt;version&gt;2.2.1.RELEASE&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.projectlombok&lt;/groupId&gt;
          &lt;artifactId&gt;lombok&lt;/artifactId&gt;
          &lt;optional&gt;true&lt;/optional&gt;
          &lt;version&gt;1.18.12&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.security&lt;/groupId&gt;
          &lt;artifactId&gt;spring-security-core&lt;/artifactId&gt;
          &lt;version&gt;5.2.2.RELEASE&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-data-mongodb&lt;/artifactId&gt;
          &lt;version&gt;2.2.4.RELEASE&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;com.google.protobuf&lt;/groupId&gt;
          &lt;artifactId&gt;protobuf-java-util&lt;/artifactId&gt;
          &lt;version&gt;3.11.4&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;com.google.protobuf&lt;/groupId&gt;
          &lt;artifactId&gt;protobuf-java&lt;/artifactId&gt;
          &lt;version&gt;3.11.4&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;io.grpc&lt;/groupId&gt;
          &lt;artifactId&gt;grpc-all&lt;/artifactId&gt;
          &lt;version&gt;1.27.1&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;com.google.guava&lt;/groupId&gt;
          &lt;artifactId&gt;guava&lt;/artifactId&gt;
          &lt;version&gt;28.2-jre&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;net.devh&lt;/groupId&gt;
          &lt;artifactId&gt;grpc-spring-boot-starter&lt;/artifactId&gt;
          &lt;version&gt;2.6.2.RELEASE&lt;/version&gt;
      &lt;/dependency&gt;
  &lt;/dependencies&gt;
  </code></pre>
  
  <p>Thanks for all recommendations.</p>