ZipException when moving project from mac to windows

[taranaki]

This is the exact error message I get:

Starting Jetty on port 8888
[WARN] Failed startup of context
com.google.gwt.dev.shell.jetty.JettyLauncher
$WebAppContextWithReload@13bd574{/,C:\Users\sk\workspace\Project\war}
java.util.zip.ZipException: error in opening zip file
at java.util.zip.ZipFile.open(Native Method)
at java.util.zip.ZipFile.<init>(Unknown Source)
at java.util.jar.JarFile.<init>(Unknown Source)
at java.util.jar.JarFile.<init>(Unknown Source)
at
org.mortbay.jetty.webapp.TagLibConfiguration.configureWebApp(TagLibConfiguration.java:
168)
at
org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:
1217)
at
org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:
513)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:
448)
at com.google.gwt.dev.shell.jetty.JettyLauncher
$WebAppContextWithReload.doStart(JettyLauncher.java:447)
at
org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
39)
at
org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:
130)
at
org.mortbay.jetty.handler.RequestLogHandler.doStart(RequestLogHandler.java:
115)
at
org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
39)
at
org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:
130)
at org.mortbay.jetty.Server.doStart(Server.java:222)
at
org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:
39)
at
com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:
542)
at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:431)
at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1053)
at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:795)
at com.google.gwt.dev.DevMode.main(DevMode.java:282)

There was a very similar post in 2009 in this group, but unfortunately
no answer.

In the whole project I do not use any zip files except for the
libraries (jar files: mallet, mallet-deps, lucene-core-2.4.0, json-
simple-1.1). I have checked that these are not corrupted.

I use GWT 2.1.1 on Windows 7.

Any help is very welcome.