Noisy error at startup

Quite often, starting a Vaadin 7.4 application I get the following error which waste some also some time.
I noticed it from 7.4.
Coud someone explai me how can I avoid it ?
Tks
Tullio

AVVERTENZA: Error persisting scss cache I:\RubikIde\workspaces\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\ide-app\VAADIN\themes\base-theme\styles.scss.cache
java.io.FileNotFoundException: I:\RubikIde\workspaces\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\ide-app\VAADIN\themes\base-theme\styles.scss.cache (Impossibile trovare il percorso specificato)
    at java.io.FileOutputStream.open0(Native Method)
    at java.io.FileOutputStream.open(FileOutputStream.java:270)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
    at com.google.gwt.thirdparty.guava.common.io.Files$FileByteSink.openStream(Files.java:201)
    at com.google.gwt.thirdparty.guava.common.io.Files$FileByteSink.openStream(Files.java:189)
    at com.google.gwt.thirdparty.guava.common.io.ByteSink$AsCharSink.openStream(ByteSink.java:163)
    at com.google.gwt.thirdparty.guava.common.io.CharSink.write(CharSink.java:110)
    at com.google.gwt.thirdparty.guava.common.io.Files.write(Files.java:477)
    at com.vaadin.server.VaadinServlet.persistCacheEntry(VaadinServlet.java:1304)
    at com.vaadin.server.VaadinServlet.serveOnTheFlyCompiledScss(VaadinServlet.java:966)
    at com.vaadin.server.VaadinServlet.serveStaticResourcesInVAADIN(VaadinServlet.java:734)
    at com.vaadin.server.VaadinServlet.serveStaticResources(VaadinServlet.java:704)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:343)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

Nobody can help ?
Tks

I'm facing this too at the moment, although it's apparently harmless.

I found this ticket on Trac https://dev.vaadin.com/ticket/16949 which seems to cover this.
For what it's worth, I'd vote for the ability to disable Scss caching altogether. :)

Cheers,

I migrated to 7.5.2 but the problem is still there.
Looking for the error the indicated directory doesn't exist.
I don't know if this is an Eclipse or a Vaadin problem.
Could someone help ?
Tks

The problem seems to be related to the fact that I've a separate project for the widgetset and a separate project for the theme.
Could someone suggest how to avoid such problem.
Tks