Valo trouble after update to 8.1.1

Since I upgraded to vaadin 8.1.1 I can’t seem to make the theme compilation work.

When running the app the site brings up an error popup after a while, stating that the widget set can’t be found.

And indeed, there seems to be an issue on compilation of the theme, however I can’t make any sense out of it:

Compiling theme "VAADIN/themes/valo-swop" failed (com.vaadin:vaadin-maven-plugin:8.1.1:compile-theme:default:generate-resources)

org.apache.maven.plugin.MojoExecutionException: Compiling theme "VAADIN/themes/valo-swop" failed
    at com.vaadin.integration.maven.CompileThemeMojo.processTheme(CompileThemeMojo.java:69)
    at com.vaadin.integration.maven.AbstractThemeMojo.doExecute(AbstractThemeMojo.java:43)
    at org.codehaus.mojo.gwt.shell.AbstractGwtShellMojo.execute(AbstractGwtShellMojo.java:182)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:331)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl$11.call(MavenImpl.java:1362)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl$11.call(MavenImpl.java:1)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:177)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:112)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:1360)
    at org.eclipse.m2e.core.project.configurator.MojoExecutionBuildParticipant.build(MojoExecutionBuildParticipant.java:52)
    at com.vaadin.integration.eclipse.maven.VaadinMojoExecutionBuildParticipant.build(VaadinMojoExecutionBuildParticipant.java:87)
    at org.eclipse.m2e.core.internal.builder.MavenBuilderImpl.build(MavenBuilderImpl.java:137)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$1.method(MavenBuilder.java:172)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$1.method(MavenBuilder.java:1)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod$1$1.call(MavenBuilder.java:115)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:177)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:112)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod$1.call(MavenBuilder.java:105)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:177)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:151)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:99)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod.execute(MavenBuilder.java:86)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder.build(MavenBuilder.java:200)
    at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:735)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:206)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:246)
    at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:301)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:304)
    at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:360)
    at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:383)
    at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:142)
    at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:232)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)
Caused by: org.codehaus.mojo.gwt.shell.JavaCommandException: Command [[
/bin/sh -c '/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/bin/java' '-Xmx1G' 'com.vaadin.sass.SassCompiler' '/Users/fs/Development/swop/Code/src/main/webapp/VAADIN/themes/valo-swop/styles.scss' '/Users/fs/Development/swop/Code/src/main/webapp/VAADIN/themes/valo-swop/styles.css'
]] failed with status 1
    at org.codehaus.mojo.gwt.shell.JavaCommand.execute(JavaCommand.java:330)
    at com.vaadin.integration.maven.CompileThemeMojo.processTheme(CompileThemeMojo.java:65)
    ... 35 more

I also had a look on the vaadin-themes-8.1.1.jar . It is not viewable, Eclipse is telling me " invalid LOC header (bad signature)
Did anybody experience similar problems? Is there any hint what I could do?

Cheers,
Florian

The issue had been with the valo-themes-8.1.1.jar
As it seems my maven instance had a corrupt downlaod of one of the crucial files – removing the jar from my local maven repository just did the trick.