Deployment error: Client Error (400)

[escion]

I have an issue when I try to deploy my app on Google App Engine (using Eclipse). This is the log:

Unable to update:

java.io.IOException: Error posting to URL: https://appengine.google.com/api/appversion/create?app_id=ConsorzioProdottiBiologici&version=1&

400 Bad Request

Client Error (400)

The request is invalid for an unspecified reason.

at com.google.appengine.tools.admin.AbstractServerConnection.send(AbstractServerConnection.java:245)

at com.google.appengine.tools.admin.AbstractServerConnection.post(AbstractServerConnection.java:207)

at com.google.appengine.tools.admin.AppVersionUpload.send(AppVersionUpload.java:639)

at com.google.appengine.tools.admin.AppVersionUpload.beginTransaction(AppVersionUpload.java:446)

at com.google.appengine.tools.admin.AppVersionUpload.doUpload(AppVersionUpload.java:137)

at com.google.appengine.tools.admin.AppAdminImpl.doUpdate(AppAdminImpl.java:284)

at com.google.appengine.tools.admin.AppAdminImpl.update(AppAdminImpl.java:48)

at com.google.appengine.eclipse.core.proxy.AppEngineBridgeImpl.deploy(AppEngineBridgeImpl.java:265)

at com.google.appengine.eclipse.core.deploy.DeployProjectJob.runInWorkspace(DeployProjectJob.java:144)

at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38)

at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)

Thanks in advance.