What to do if sonarqube fails due to negative SQALE density value - sonarqube

Question

We have upgraded to SonarQube 5.1 and analyze our huge multi-module project with it using Maven. While for several runs the analysis was successful, since some days we now get:
[ERROR] Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.6:sonar (default-cli) on project jahia-dev-root: The SQALE density value should be between 0 and 1.7976931348623157E308 and got -0.004 -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.6:sonar (default-cli) on project jahia-dev-root: The SQALE density value should be between 0 and 1.7976931348623157E308 and got -0.004
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:217)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.MojoExecutionException: The SQALE density value should be between 0 and 1.7976931348623157E308 and got -0.004
at org.codehaus.mojo.sonar.bootstrap.ExceptionHandling.handle(ExceptionHandling.java:41)
at org.codehaus.mojo.sonar.bootstrap.RunnerBootstraper.execute(RunnerBootstraper.java:139)
at org.codehaus.mojo.sonar.SonarMojo.execute(SonarMojo.java:132)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
... 19 more
Caused by: The SQALE density value should be between 0 and 1.7976931348623157E308 and got -0.004
From the log the last sub-module analyzed was a webapp without java files, but just groovy, jsp, javascript and xml files. Anyone has an idea, if there is a workaround or how to proceed solving that problem?
We have upgraded plugins to Java 3.3, Groovy 1.1.1, XML 1.3 last week. Could it be related?
UPDATE 14.07.2015: I found that switching to Default XML Profile with 0 rules activated solved the problem. Before I had the following XML rules active:
Newlines should follow each element
Source code should be indented consistently
Tabulation characters should not be used
I still don't know why activating these XML rules runs into that exception.