Jenkins build is throwing unexpected error like :

07:01:45 [INFO] User cache: C:\Users\svc_enbuild\.sonar\cache
07:01:45 [INFO] SonarQube version: null
07:01:45 [INFO] ------------------------------------------------------------------------
07:01:45 [INFO] BUILD FAILURE
07:01:45 [INFO] ------------------------------------------------------------------------
07:01:45 [INFO] Total time: 12.735s
07:01:45 [INFO] Finished at: Mon Oct 26 07:01:45 PDT 2015
07:01:45 [INFO] Final Memory: 30M/447M
07:01:45 [INFO] ------------------------------------------------------------------------
07:01:45 [ERROR] Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.7:sonar (default-cli) on project rrm-operational: null: MojoExecutionException: NullPointerException -> [Help 1]
07:01:45 org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.7:sonar (default-cli) on project rrm-operational: null

The day before its working fine. Build is using sonar-maven-plugin of version 2.7 (default). So looks like something changed in this particular version of jenkins sonar maven plugin.

This blocks us to do a source code scan and code quality assessment.
Please suggest here.