Updating theme "VAADIN/themes/mytheme" failed:

Running the example from the Vaadin Get Started command results in above error

mvn -B archetype:generate -DarchetypeGroupId=com.vaadin -DarchetypeArtifactId=vaadin-archetype-application -DarchetypeVersion=8.1.1 -DgroupId=org.test -DartifactId=vaadin-app -Dversion=1.0-SNAPSHOT cd vaadin-app mvn package jetty:run the output looks like this:

[code]
MacBookPro:vaadin-app geraldfuchs$ mvn package jetty:run

[INFO]
Scanning for projects…

[WARNING]
The project org.test:vaadin-app:war:1.0-SNAPSHOT uses prerequisites which is only intended for maven-plugin projects but not for non maven-plugin projects. For such purposes you should use the maven-enforcer-plugin. See https://maven.apache.org/enforcer/enforcer-rules/requireMavenVersion.html

[INFO]

[INFO]

[INFO]
Building vaadin-app 1.0-SNAPSHOT

[INFO]

[INFO]

[INFO]
— vaadin-maven-plugin:8.1.1:update-theme (default) @ vaadin-app —

[INFO]
Updating theme VAADIN/themes/mytheme

[ERROR]
Fehler: Hauptklasse com.vaadin.server.themeutils.SASSAddonImportFileCreator konnte nicht gefunden oder geladen werden

[ERROR]
Updating theme “VAADIN/themes/mytheme” failed

org.codehaus.mojo.gwt.shell.JavaCommandException: Command [[

/bin/sh -c ‘/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/bin/java’ ‘-Xmx1G’ ‘com.vaadin.server.themeutils.SASSAddonImportFileCreator’ ‘/Users/geraldfuchs/eclipse-workspace/vaadin-app/src/main/webapp/VAADIN/themes/mytheme’

]] failed with status 1

at org.codehaus.mojo.gwt.shell.JavaCommand.execute(JavaCommand.java:330)

at com.vaadin.integration.maven.UpdateThemeMojo.processTheme(UpdateThemeMojo.java:45)

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.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)

at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)

at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)

at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)

at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)

at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)

at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)

at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:309)

at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:194)

at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:107)

at org.apache.maven.cli.MavenCli.execute(MavenCli.java:993)

at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:345)

at org.apache.maven.cli.MavenCli.main(MavenCli.java:191)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)

at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)

at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)

at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)

[INFO]

[INFO]
BUILD FAILURE

[INFO]

[INFO]
Total time: 1.804 s

[INFO]
Finished at: 2017-08-15T16:02:57+02:00

[INFO]
Final Memory: 16M/224M

[INFO]

[ERROR]
Failed to execute goal com.vaadin:vaadin-maven-plugin:8.1.1:update-theme (default) on project vaadin-app: Updating theme “VAADIN/themes/mytheme” failed: Command [[

[ERROR]
/bin/sh -c ‘/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/bin/java’ ‘-Xmx1G’ ‘com.vaadin.server.themeutils.SASSAddonImportFileCreator’ ‘/Users/geraldfuchs/eclipse-workspace/vaadin-app/src/main/webapp/VAADIN/themes/mytheme’

[ERROR]
]] failed with status 1

[ERROR]
→ [Help 1]

[ERROR]

[ERROR]
To see the full stack trace of the errors, re-run Maven with the -e switch.

[ERROR]
Re-run Maven using the -X switch to enable full debug logging.

[ERROR]

[ERROR]
For more information about the errors and possible solutions, please read the following articles:

[ERROR]
[Help 1]
http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
[/code]does anyone know how to solve this?

deleteung my .m2 folder solved this problem.

How ?

What is deleteung ?

BY m2, do you mean the enviroment variable for maven ?

Thx Gerald, had same problem.Clearing .m2 folder fixed it.