This possible is the Eclipse cache problem when you have some update in your POM file.
To solve the problem, you will need:
1. close the eclipse
2. delete the .project and .settings file under your project folder
2. run 'mvn eclipse:clean' in terminal under your project folder
3. delete the eclipse workspace file or the .metadata file under the workspace
4. reopen the eclipse with command '-clean'
Problem will be solved perfect.
