Upon upgrading from 1.523 to 1.525 (skipped 1.524) The Invoke Standalone Sonar Analysis field shows "Needs to know where your Sonar is installed. Please do so from the system configuration." In the Sonar Installation field.

The system configuration screen has a sonar runner installation configured.

Jenkins Sonar jobs fail with:
FATAL: null
java.lang.NullPointerException
at hudson.plugins.sonar.SonarInstallation.all(SonarInstallation.java:38)
at hudson.plugins.sonar.SonarInstallation.get(SonarInstallation.java:46)
at hudson.plugins.sonar.SonarRunnerBuilder.isSonarInstallationValid(SonarRunnerBuilder.java:285)
at hudson.plugins.sonar.SonarRunnerBuilder.perform(SonarRunnerBuilder.java:187)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:19)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:804)
at hudson.model.Build$BuildExecution.build(Build.java:199)
at hudson.model.Build$BuildExecution.doRun(Build.java:160)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:586)
at hudson.model.Run.execute(Run.java:1593)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:247)

This all worked on 1.523. I have tried removing and re-adding the Sonar installation from the system configuration and from the job. Neither have solved the problem.