Exception in WarningsPlugin

Builds are finishing with a failure result, and the following exception is being shown:

[WARNINGS] Parsing warnings in console log...
ERROR: Publisher hudson.plugins.warnings.WarningsPublisher aborted due to exception
java.lang.NullPointerException: Name is null
at java.lang.Enum.valueOf(Enum.java:195)
at hudson.plugins.analysis.util.model.Priority.valueOf(Priority.java:18)
at hudson.plugins.analysis.core.HealthAwarePublisher.getMinimumPriority(HealthAwarePublisher.java:522)
at hudson.plugins.analysis.core.AbstractHealthDescriptor.<init>(AbstractHealthDescriptor.java:36)
at hudson.plugins.warnings.WarningsHealthDescriptor.<init>(WarningsHealthDescriptor.java:25)
at hudson.plugins.warnings.WarningsResultAction.<init>(WarningsResultAction.java:31)
at hudson.plugins.warnings.WarningsPublisher.perform(WarningsPublisher.java:202)
at hudson.plugins.analysis.core.HealthAwarePublisher.perform(HealthAwarePublisher.java:280)
at hudson.tasks.BuildStepMonitor$2.perform(BuildStepMonitor.java:27)
at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:603)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:582)
at hudson.maven.MavenModuleSetBuild$RunnerImpl.post2(MavenModuleSetBuild.java:651)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:529)
at hudson.model.Run.run(Run.java:1349)
at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:349)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:139)

If I disable the warnings publisher from the job configuration, the build ends successfully.

Here is the config section of the warnings plugin of the job:

<hudson.plugins.warnings.WarningsPublisher>
<pluginName>[WARNINGS] </pluginName>
<defaultEncoding></defaultEncoding>
<canRunOnFailed>false</canRunOnFailed>
<useDeltaValues>false</useDeltaValues>
<thresholds>
<unstableTotalHigh></unstableTotalHigh>
<unstableTotalNormal></unstableTotalNormal>
<unstableTotalLow></unstableTotalLow>
<unstableNewHigh></unstableNewHigh>
<unstableNewNormal></unstableNewNormal>
<unstableNewLow></unstableNewLow>
<failedTotalHigh></failedTotalHigh>
<failedTotalNormal></failedTotalNormal>
<failedTotalLow></failedTotalLow>
<failedNewHigh></failedNewHigh>
<failedNewNormal></failedNewNormal>
<failedNewLow></failedNewLow>
</thresholds>
<pattern></pattern>
<parserNames>
<string>Java Compiler</string>
</parserNames>
<ignoreConsole>false</ignoreConsole>
</hudson.plugins.warnings.WarningsPublisher>